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THE COMMON SIGHTS IN 
THE HEAVENS, 

AND HOAV TO SEE AND KXOW THEM, 



CAPTAIN A. W.^^DRAYSOX, E.A, 



}^^^ 



LONDON: 

CHAPMAN AND HALL, 193 PICCADILLY. 

1862. 






LOKDON : PRINTED BT WILLIAM CLOWES AND SONS, STAMFORD STRKET. 



PEEFACE. 



In the following pages will he found a simple 
description of the various sights which can be 
viewed in the heavens during the day and 
night. 

When possible the pencil has been used to 
aid the description given by the pen. 

This book merely pretends to give an ac- 
count of those objects which may be seen with 
a common telescope^ or even by the unaided 
eye. All scientific terms have been as much 
avoided as possible ; and although in some 
instances diagrams which look suspicious^ and 
appear to tend towards geometry, have been 
inserted, still a moment's examination will, we 
trust, prove their innocence, and show that 



IV PEEFACEo 

they are quite intelligible even to the most 
unmathematical mincL 

Under these circumstances it is hoped that 
all readers may be able to understand and to 
feel an interest in those subjects which are here 
lightly touched upon. 



COMMON SiaHTS IN THE 
HEAVENS. 



CHAPTEE I. 

Every person who possesses sight is provided 
with the means of perceiving a whole host of 
interesting and beautiful celestial objects. If 
the same individual is disposed to spare a few 
minutes during the many clear nights in the 
year, to the examination of the various hea- 
venly bodies, he will shortly become possessed 
of such an amount of information that a new 
sphere of investigation will be introduced to 
him. If, in addition to these natural gifts, 
he is fortunate enough to be provided with a 
comm^on telescope, or possesses about three 
pounds of s]3are cash, so as to provide himself 



^ COMMON SIGHTS 

with one, he is then armed with sufficient 
means to enable him to examine closely the 
chief characteristics of those vast floating bodies 
which, night after night, apparently move 
around this world, and reveal their wonders to 
the gaze of the inquirer. 

It is a common, but at the same time a very 
mistaken idea, that all which appertains to the 
celestial bodies, their movements, condition, 
and positions at various times, is of such a com- 
plicated and puzzling nature, that very few 
minds are capable of comprehending even the 
elements of the science which treats of this 
subject. Hence very few individuals are dis- 
posed, or can afford, to devote several year^ of 
exhausting study to acquire a knowledge of 
mathematics, geometry, G-reek, and the many 
other sciences which they believe are requisite 
to be known, before they can comprehend even 
the common interesting portion of that vast 
page, which extends from the horizon to the 
point above us in the heavens. 

To comprehend the science of astronomy (as it 



IN THE HEAVENS. d 

is taught) requires of course a considerable pre- 
paration ; but to be able to enjoy the fruit of 
this science requires little more than eyes, a 
telescopCj and a few minutes' attention. 

There are several other subjects ^Yhich may 
be said to really occupy nearly the same posi- 
tion as that assumed for astronomy. Walking, 
for instance, is a very healthy and useful occu- 
pation. If, ho^Yever, no person was allowed to 
walk, or believed that he could not do so until 
he knew exactly what muscles, nerves, and 
joints he called into action, — could explain how 
the will, by a mysterious agency, acted upon 
the matter composing the body and legs, how 
much air was displaced by the motion of the 
body, &c., — we might all become very scientific 
people ; but probably should soon become im- 
becile, although we might possibly look with 
contempt upon the healthy countryman who 
walked ably, but who knew not the science of 
that which he was doing. 

Thus to be able to understand the peculiar 
beauties of the most interesting objects in the 



4 COMMON SIGHTS 

heavens, is within the grasp of certainly ninety- 
nine out of every hundred individuals, althougli 
they may be entirely unacquainted with science, 
but possess merely common observation. 

There are in the heavens a variety of beauti- 
ful objects. During the day there is the glow- 
ing sun, w^hose heat and light are essential to 
the production and continuation of animal and 
vegetable life, whose rays gladden and enliven 
the earth, and whose daily advent calls forth 
an harmonious song of praise from a myriad 
feathered songsters. 

With a calm, subdued light the crescent- 
shaped moon may also be seen in the day-time, 
perhaps half her illuminated surface being then 
turned towards the earth. 

When the mighty orb of day has run his 
course, and has retired from that part of the 
heavens which appears arched above us, then 
thousands of less gorgeous objects timidly peep 
forth from their concealment, and, perceiving 
the earth in shadow, they hasten to display 
their pale, brilliant fires, until at last the 



IN THE HEAVENS. O 

heaveiis appear studded with thousands upon 
thousands of sparklmg lights, which, although 
smaller, are scarcely less bright than the mid- 
day sun. 

The evening and the night are the periods 
when the heavens yield most abundantly a 
field for amusement, and it is then that the 
wonders revealed therein can be most calmly 
contemplated. The lover of natm-e, whose 
thoughts are given to the examination of terres- 
trial wonders only, is not able to roam during the 
darkness of night, and perceive those beauties 
for which he may be in search ; neither can he, 
during the somewhat long periods of darkness in 
winter, find many of those interesting natural 
objects which abound in summer. Yet it is in 
these very seasons and times that the heavens 
offer us so fruitful a source of amusement, and 
reveal to our gaze so many subjects upon which 
we may employ our thoughts and researches. 

Our interest in the celestial bodies is much 
increased when we know that many of these 
are worlds like that on which we live, and that 



(J COMMON SIGHTS 

they differ apparently from it merely in some 
minor details, or in the presence or absence of 
certain conditions, which will be, or may have 
been, those of tliis globe in the coming ages of 
the future, or in the no less vast and mysterious 
epochs of the past. 

To the most su23erficial observer, there appear 
to be merely three descriptions of bodies in the 
heavens, viz., the sun, the moon, and the stars. 
The latter appear to vary from each other in 
size and brightness as well as in colour ; but 
unless some slight attention be directed to 
them, they seem to present very little variety. 

Observation, however, has shown that the so- 
called stars must be divided into two classes : 
the first comprises those bodies which always 
maintain the same position with regard to each 
other, and which are at an immense distance 
from our world, and wliich shine by means of 
some property inherent in themselves. The 
second class consists of those so-called stars 
which move amongst the other stars, and 
which, it is found, are at certain calculable dis- 



IX THE HEAVENS. 7 

tances from our earth, and which only shine or 
appear bright because the sun shines upon them. 

Those of the first class are called ''fixed 
stars,'' those of the second " -planets ^ * 

It is found that all the planets move around 
the sun ; that they all spin round, or rotate, as 
it is termed, and that thev are all somewhat of 
the shape of an orange. 

Many of the planets are attended by certain 
bodies termed satellites, which move around 
them just as the planets move round the sun ; 
these attendants are called " satellites,'' " moons," 
or " secondaries ;" our moon being a satellite 
or secondary to the earth. 

The sun, the planets which move round him, 
and their satellites or moons, are termed the 
solar system, which is thus like one family ; the 
sun the apparent father, or head, the various 
planets the children, whilst the satellites are 
the grandchildren. 

The sun and full moon appear to us nearly 
of the same size, whilst the various planets 

* Fi'om 2^^cinetes, wanderers. 



8 COMMON SIGHTS 

differ considerably in their visible dimensions. 
Appearances are proverbially deceitful, and the 
proverb holds good most effectually when ap- 
plied to the celestial bodies. The proportional 
difference between the size of the sun and the 
moon, is about that which exists between the 
' Great Eastern ' steam-ship and a little boy's 
toy -boat ; the simiUtude in their apparent size 
being due to the difference in distance from the 
earth between the two. We can easily com- 
prehend the effect of distance in altering the 
apparent size of objects if we look through 
our window, where the pane of glass close to us 
looks larger than a church at a distance. 

The various planets differ in their size, al- 
though not so much as the moon and the sun. 
Still there are some which would cause our 
earth to look a very insignificant object if the 
two were placed side by side, and examined 
from a distance. 

The accompanying table will show the rela- 
tive diameter of the sun and the eight primary 
planets, of wiiich the solar system consists. 



IN THE HEAYEXS. 







Miles. 


Sun 


about 


888,646 


Jupiter . 


;, 


89,000 


Satui^n . 


if 


76,000 


Xeptune 


J? 


37,500 


Uranus . 


?-■» 


35,000 


Eartli . 


?? 


7,912 


Venus . 




7,800 


Mars 


?5 


4,189 


Mercury 


?J 


3,140 



There are, besides, a number of small planets 
which revolve round the sun, and are really 
primaries: these, however, are not considered 
to rank amongst the eight leading planets in 
the system ; they are very small, and present 
peculiarities ^vhich distinguish them from the 
principal members, and they are, besides, 
scarcely visible unless with the aid of a tele- 
scope. Five of the principal planets, viz., 
Mercury, Yenus, Mars, Jupiter, and Saturn, 
can be plainly seen with the unaided eye, 
Uranus is also visible, as a rather dim object ; 
but, with the aid of a large telescope, reveals a 
circular and planetary form. 



10 



COMMON SIGHTS 



These planets all move round the sun, and 
at different distances ; the relative position of 
each is shown below. 




A different scale is now used to show the 
distant planets, Jupiter's distance being giA'en. 



THE SU]S^ 
Solax Spots . 



PL2. 





■fe-eni ^ooki indi. 

Changes in a Solar Spot passing across Suns disc. 



IN THE HEAVENS. 11 



CHAPTEK II. 



THE SUN. 



Every person must have observed that the sun 
is higher in the heavens at midday in summer 
than in winter, and that it remains longer above 
the horizon in summer than in winter. If the 
sun be observed during twelve months, it will 
be found that about the 22nd of December, at 
midday, it will be lower down than at any other 
time in the year ; and about June the 21st it 
will be higher up than at any other time. 

If we could make two marks in the sky to 
show the two places where the sun reached at 
midday, on the 21st of June and 21st of De- 
ceinber, we should find that about the 20th of 
March and the 22nd of September the sun was 
just midway between these marks. 

If we measured TOth an instrument the dailv 



12 COMMON SIGHTS 

height of the sun, which is always greatest at 
midday, we should find that, early in January, 
the sun increased its height yeiy slowly from 
day to day, and that during a week it yaried a 
very little more than its own diameter. 

Then it would go on increasing more quickly 
until March the 20th, when, durir^g one day, 
there would be an increase in height equal to 
nearly the sun's diameter. 

After this date there would be a gradual de- 
crease in the rate until June, although still a 
daily increase in height. 

AATien, then, we haye passed the shortest day, 
we do not observe any very great difference in 
the length of sunlight during a few days ; then 
there is a slow and steady increase, the dif- 
ference being greatest during the month of 
March, when the days increase rapidly in lengi:h ; 
after this date there is still a gradual increase, 
but the rate is not so 2:reat. In fact, durinsf 
the thirty days in March, as great a change 
occurs in the sun's midday height as there is 
during the ten days of December, the thirty- 



IN THE HEAVENS. 13 

one days of January, and the eleven days of 
February. So that in thirty days of March 
there is as great a change as during the fifty- 
two days from the 21st of December on to the 
11th of February. 

After the 21st of June the daily greatest 
height of the sun begins to decrease, and in a 
manner exactly similar to that in which it in- 
creased, viz., slowly at first, and quickest when 
about midw^ay in its course of descent. Thus, 
in September, there is a very rapid decrease, 
just as in March there was an increase in the 
daily height of the sun ; then the rate of de- 
crease becomes less, until the 21st of Decem- 
ber. 

These changes occur year after year with 
regularity, no difference being observed unless 
the most accurate instruments are employed. 

The cause of the sun's variation in height is 
the movement of the earth round the sun, and 
in a sort of up-and-down manner. Thus, if w^e 
call the northern half of the world the upper 
half, and the southern half the loiver^ then we 



14 COMMON SIGHTS 

may say that on the 21st of December ^Ye are 
above the smi considerably ; from this elate to 
the 21st of June the earth moves downwards, 
and round a circle, in the centre of which is 
the sun. On the 21st of March the earth is 
level with the sun. From the 21st June to 
the 21st December the earth moves upwards, 
and is again level with the sun on the 21st of 
September. 

By means of a common hoop, we may see 
why the sun rises and falls each day, more 
quickly, in March and September, than at other 
times of the vear. 









^ 3-^,.^ 

4.'--^,. 



3"; A 



Thus, suppose D M J S a hoop resting on a 



IN THE HEAVENS. 15 

table J, and propped up at D above the t<tl:'le, 
and suppose C the centre of this hoop. If we 
moved anything from 1) to 1. it would not have 
moved doivnwards very much, because this part 
of the hoop is nearly level. As this same thing 
moved from 1 to 2, it would have moved down- 
wards much more, although the distances from 
D to 1 and from 1 to 2 were equal From 2 
to 3 there would be a more rajfid fall, whilst 
from 3 to 4 a more gradual descent. At X the 
body would be level with C, at D above it. and 
at J below it. 

This is just the eom\se that the earth pursues 
round the sim ; D being the December, M the 
March, J the June, and S the September posi- 
tion ; C being the position oi the sim. 

The earth is distant from the smi about 
ninety-five million miles, a distance which would 
occupy an express train about two hundred years 
to travel. In consequence of the earth movinj^- 
round the sim, our annual journey amounts to 
nearly six hundred millie^n miks : thus each day 
of our lives we travel more than a million and 



16 COMMON SIGHTS 

a half miles through space, or a distance equal 
to about sixty times round the earth. 

If we stand at some railway crossing and see 
an express train rush past, the iron horse snort- 
ing and wdiistling, the dust flying, the wind 
almost knocking us do^\Ti, and then observe the 
passengers reclining calmly in the carriages, or 
talking to each other, we cannot well fail to 
ponder upon the singular anomaly thus presented 
to us. There is a mass of carriages which appears 
to be jolting and crashing onwards to destruc- 
tion, at the rate of nearly fifty miles an hour, 
and yet the most timid of the occupants of the 
carriage appears to suffer no alarm. This is cer- 
tainly a grand sight, although we are familiarized 
to it, and therefore are but slightly impressed 
with the indication of power thus manifested. 
If, however, an express train dashing past us 
is at all a source of admiration, how much more 
impressed we should be, were we able to 
observe from space, a vast world which would 
come rushing and spinning past us, with a ve- 
locity of sixty-eiglit thousand miles an hour ! 



IX THE HEAYEXS. 17 

Every human being, therefore, is a great tra- 
veller, although he may repose in his arm-chaii' 
from day to day. The cannon-ball that moves 
too quickly to be seen is merely a slow coach 
compared to the world upon which we live, and 
our world is slow when compared to the little 
planet 3Iercury, whose rate is nearly double 
that of the earth. 

At noon the sun will be south of all localities 
in England. The sun appears to move round 
the earth in twenty-four hours; therefore, in 
six hours it moves round one fourth of the 
earth, and consequently will be found near the 
Avest at six o'clock in the evening, and near the 
east at six o'clock in the morning. If we know 
the time, therefore, and can see the sim, we 
can always tell where the cardinal points of 
the compass are situated ; for as the sun is 
south at noon, and near the east at 6 a.m.. 
it would be nearly south-east at 9 A.ir., between 
south-east and south at half-past 10 A.:yi., and 
so on. 

If the time of sunrise be added to that of 

c 



18 COMMON SIGHTS 

sunset, the sum of the two will nearly always 
amount to twelve. Thus, if the sun rise at 
8 A.M., it will set about 4 p.m. ; and if it rise 
at 5 A.M., it will set about 7 p.m. : thus, if we 
know the time of sunrise we may obtain that 
of sunset, or vice versa, because the sum of the 
two should amount to twelve. 

We will first call attention to those interest- 
ing facts which may be seen by the unaided 
eye, before v»'e refer to those which require 
some artificial means to enable a person to 
see them distinctly. 

Among the most singular phenomena con- 
nected with the sun, the midnight sun to an in- 
habitant from the central portions of the globe 
must appear at first very curious. In England 
we are accustomed to have twilight from about 
the 21st of May until the 21st of July, during 
which period the nights are nearly as light as 
many of our November days. This, however, is 
very different from seeing the sun above the 
horizon at midnight, and shining as brightly as 
he does in England towards the afternoon of 



IN THE HEAVENS. 19 

an autumn day. To view the midnight sun we 
must trayel to within about twenty-three and a 
half degrees from the north or south poles — that 
is, we must travel to about sixty-six and a half 
degrees of north or south latitude. In Spitz- 
bergen, the north of Iceland, the north of 
Norway, in Baffin's Bay and Greenland, the 
midnight sun will be visible during June. 
The farther north that we go from England, 
the lighter will be the nights during the sum- 
mer. 

When w^e are at the central — i. e,, the equa- 
torial — latitudes of the earth, we have the sun 
directly overhead dming midday in March and 
September, and a very little way from the 
same point during midday in June and De- 
cember. 

The nights at the equator are dark as 
Erebus. If the moon does not shine, and if 
there be a few clouds to cause the stars to look 
dim, then an English winter's night is twilight 
compared to the summer night at the equator. 

At sunset, also, the sun, instead of passing 



20 COMMON SIGHTS 

obliquely below the horizon, descends perpen- 
dicularly — so that twilight has scarcely any 
existence at or near the equator. 

In England, and in localities in the northern 
half of the world, it is customary to talk about 
turning a screw, or dealing at whist, &c., with 
the sun — that is, from left hand to right. 
When, however, we have crossed the equator, 
and have travelled some sixteen hundred miles 
on the other side, these directions become 
incorrect, for the sun there appears to rise from 
the right hand and to set on the left, and to 
pass at all times of the year from right to left, 
instead of from left to right. 

Exactly the same change in right and left 
movement would occur if a weight were to be 
swung backwards and forwards between two 
people who were standing face to face. Each 
time the weight moved to the right of the one 
person it would move to the left of the other, 
and vice versa. 

This change in the apparent movement of 
the sun having been observed is a rather con- 



IN THE HEAVENS. 21 

vincing proof that the Phoenicians rounded the 
Cape of Good Hope as long ago as 400 B.C. — 
that is, upwards of U\o thousand two hundred 
and sixty years ago ; for Herodotus states that 
there were some travellers who sailed down the 
Eed Sea and returned by Gibraltar, and stated 
a thing which he could not believe, though 
others might — viz., that during their journey 
they observed the sun rise from their right 
hand and set upon their left. 

This fact was not likely to be guessed at by 
sailors had they not seen it, especially in an 
age when it was thought unscientific and foolish 
to beheve that the earth was spherical instead 
of a plane, and when scarcely a single traveller 
had crossed the equator, or even ventured 
within the tropics. 

The sun sometimes, when rising or setting, 
appears of a blood-red colour, and of a very 
large size. If measured with an instrument at 
this period the sun is really not larger than at 
another time ; it therefore follows that there 
must be some effect produced upon the eye, 



22 COMMON SIGHTS 

which, is not a real enlargement in the actual 
size of the sun, or in its measured size. 

These considerations induced the earlier 
astronomers to believe that the large size was a 
delusion caused by the sun being compared 
with terrestrial objects when he was near the 
horizon, whilst when he was eleyated in the 
heavens there were no objects with which to 
compare him. 

A veiy little consideration would soon have 
shown that this could not be the true explana- 
tion of the phenomenon ; for in consequence of 
the sun setting every evening, and rising every 
morning, the same effects ought always to be 
observed, whereas it is only two or thi^ee times 
each year that this singular effect is seen. 

From another fact, also, the inefficiency of 
this explanation would have been manifest — 
viz., that the large red sun is observed very 
frequently at sea, when the ocean is calm as a 
lake, and no terrestrial or other objects are 
within a hundi^ed miles. 

It is far more probable that the enlarged 



IX THE HEAYEXS. 23 

appearance is due to a peculiar state of the 
atmosphere, a condition probably analogous to 
that which enables us at times to perceive quite 
distinctly distant objects, which then appear 
larger than usual. When this condition exists, 
the ^'weather-wise" prophecy a change of 
w^eather, and usually consider that rain will 
shortly fall. A register of the weather before 
and after this singular appearance of the suu 
might enable us to collect some useful facts. 

When the sun is just close to the horizon he 
appears usually to be egg-shaped, instead of 
circular, his longest portion being parallel to 
the horizon. This effect is due to what is 
called refraction. Eefraction is the term used 
to indicate the bending of the rays of light as 
they pass thi^ough the atmosphere or through 
water. The nearer any celestial body may be 
to the horizon the more would a ray of light 
from it become bent ; and thus, as the lower 
part of the sun is nearer the horizon than the 
upper part, then the light from the lower part 
becomes the more bent, whereas no difference 



24 COMMON SIGHTS 

is produced upon the horizontal width of the 
sun. The following sketch shows the appear- 
ance referred to. The sun is there shown just 
resting on the horizon, and its shape altered 
from a circle to an oval. Accordino- to the 



;# ,- 



"^^^W^^fe^ 






state of the atmosphere this apparent distortion 
increases or diminishes, but it is usually very 
considerable. The most singular fact connected 
with it is that when just visible above the 
horizon, as shown in the sketch, the sun is 
actually below the horizon, and is brought into 
view by refraction. 

A very rare and singular appearance is that 
called parhelion — near the sun. Sometimes 



IN THE HEAVENS. 25 

two, three, or more suns are visible in the 
heavens at the same time. In high latitudes 
this appearance is not uncommon, but in lower 
regions it is rarely witnessed. Aristotle men- 
tions an instance of two mock suns having been 
seen the whole day on the Bosphorus ; and 
Pliny tells of a triple sun having been seen by 
him during the reign of Claudius. Hevelius, 
an astronomer of celebrity at Dantzic, relates 
that seven mock suns were once noticed by 
him. These mock suns usually appear on each 
side of the real sun, or above and below it, and 
thus rest upon the circumference of a halo 
which surrounds the sun. 

When examined by the unaided eye the 
sun appears a brilliant luminous body, without 
a speck. If, however, a telescope be directed 
to him, and if the eye be protected by means 
of a piece of dark glass, the sun then presents 
a sort of mottled surface, which is by no means 
perfectly clear, but which appears at all times 
to be covered by a series of dark and irregular 
lines ; and at uncertain periods black spots of 



26 COMMON SIGHTS 

large size appear upon his surface. The 
smaller streaks visible on the sun do not seem 
to change in any way, nor do they offer any 
peculiarities which can serve as guides to their 
constitution. The large spots, however, are 
usually undergoing changes, and these present 
phenomena which are well suited for the foun- 
dation of speculation. 

The spots upon the sun serve to make us 
acquainted with one or two facts of interest. 
They show us that the sun turns upon its axis 
just as does the earth and the principal planets 
in the system. They indicate where the equa- 
tor of the sun is situated, and they enable us 
to find the length of time occupied during his 
rotation. 

It not unfrequently happens that a person 
possessing good sight can see with the naked 
eye some one or two spots upon the sun, pro- 
vided that a piece of coloured glass be used as 
a means to subdue his brilliancy. When taking 
altitudes with Hadley's sextant, and without a 
telescope, I have usually distinguished a spot 



IX THE HEATEXS. 27 

upon the sun ; the combined effect of the red 
and green glasses being the most favourable for 
such an examination, as the sim then appears 
to be a pale yellow, whilst the spot is black. 

It has been considered remarkable that some 
of the ancients should have known of the exist- 
ence of spots on the sun, before the telescope 
was invented ; but if any person carefully ex- 
amine the sun's smface each day by the aid of 
pieces of yellow and red, or red and green 
glass, or even look at the sun's reflection in a 
pail of water, it will appear singular how any 
observer could have omitted to notice the spots, 
as they can be easily seen with the naked eye. 
During a London fog, when the sun is only just 
visible, I have seen the spots very distinctly. 
To watch the changes which take place, and to 
see clearly the peculiarities which appertain to 
the spots, a telescope with a moderately power- 
ful magnifying power should be used, and a 
dark eye-piece fitted on to the eye end of the 
telescope. To observe any celestial body 
thoroughly, the telescope should be arranged 



28 COMMON SIGHTS 

upon some kind of stand, and protected from 
the wind. When even a telescope of average 
power is thus protected, the changes in the 
spots on the sun may be observed, and a register 
kept of the maximum and minimum quantity, 
from which some valuable facts might be 
adduced. 

To a person unacquainted with the simplicity 
of some astronomical problems, it may appear 
a very difficult matter to tell which is the sun's 
pole star, and how his equator is arranged 
relatively to that of the earth. To approxi- 
mate very closely to both these data is, how- 
ever, a very easy matter, which is accomplished 
as follows : — 

Suppose that upon a common globe we 
arrange several black spots, and then stand at 
a distance and watch these spots when the 
globe is made to turn round. If we walked 
around the globe, we could soon tell in which 
direction its axis pointed, for when we found 
the spots traced straight lines, we should then 
know that the axis was at right angles to 



IN THE HEAVENS. 



29 



these Knes, and we should consequently know 
in which direction it pointed. So is it mth 
the spots on the sun, which are found to 
trace straight lines during June and Decem- 
ber, and curved lines at all other times of the 
year. Thus, if from day to day we were to 
mark on a circle the position of the spots, we 
should find that a line joining these various 
positions would appear, as shown below, at the 
various periods indicated. 







December. 



March. 



June. 



September. 



During June and December the spots trace 
straight lines, which make an angle of about 
seven degrees with a horizontal line on the earth 
at midday. During March and September the 
spots trace curved lines. Thus from the earth 
we can look upon the north pole of the sun 
during September, and upon the south pole of 
the sun during March. 



30 COMMON SIGHTS 

K any particular spot be observed, it is 
found to move from the left across to the right 
of th.e sun. The motion is exactly that which 
would occur if the spots were fixed to a rotatory 
ball, and it is therefore only reasonable to 
conclude that the sun turns upon an axis. 

If any one spot be watched, it is found to 
return to the same position in a j)eriod a little 
over twenty-seyen days. Making the proper 
allowance for the movement of the earth 
during that time, it is found that the sun turns 
round in about twenty-five days and a half. 
The probable object of this rotation will be 
considered at a future page. 

A spot if examined with a large telescope 
is observed to undergo changes in size and 
shape, but rarely, if ever, to alter its position. 
When the spot first appears upon the left side 
of the Sim, there is usually a dark and a light 
portion, as though some reflected light were 
cast upon the side of a hollow cylinder. ^^Tien 
the spot is seen at the central portions of the 
sun, then it is all black, but usually with a 



IN THE HEAYEXS. 31 

lighter fringe. When on the right side of the 
sun, it is lighted in the same manner, only 
upon the opposite side to that upon which it was 
lighted when it became visible upon the left side. 
The sketches on Plate 2 ^vill show the apparent 
changes which usually take place in a spot as it 
is carried across the face of the sun. 

Many speculations have been made as to the 
nature of the solar spots, but up to the present 
time very Kttle is kno^Ti about them. It may 
be many years before we ascertain for certain 
whether they produce any effect upon our cli- 
mate, or upon the earth at all ; and it is pro- 
bable that until we have some other means 
than mere conjecture for arriving at truths con- 
nected with remote objects, the spots on the 
sun will still continue to be mysteries. 

From observations carried on within the last 
thirty years, there appears some probability 
that the spots are in the greatest profusion at 
intervals of about ten years, wliilst in the inter- 
mediate periods the least number have been 
observed. In the vear 1828 there were, ac- 



32 COMMOiT SIGHTS 

cording to the observations of M. Schwabe, 225 
groups of spots observed: in 1833, only 33 
groups. In tiie year 1837 there were 333 
groups seen; whilst six years afterwards, viz., 
in 1843, there were only 34. Again in 1848 
there were 330 groups seen. Thus at intervals 
of nearly ten years the maximum number of 
spots have been observed. 

It is a little singular, and it may be con- 
sidered rather beyond the range of chance, that 
the greatest magnetic changes on earth are 
found to correspond with the periods when the 
maximum and minimum number of spots are 
observed on the sun. Thus it is highly pro- 
bable that there is a connection between these 
two phenomena which may either be both the 
effects of some other great natural cause, or, as 
is more probable, that terrestrial magnetism is 
connected mth the sun's condition. 

The most popularly received idea about the 
sun's spots is, that they are openings in a 
luminous atmosphere by which he is sur- 
rounded, and that consequently it is the dark 



IN THE HEAVENS. 33 

body of the sun that is seen, in the shape of a 
spot. There is a great difficulty about this 
hypothesis, inasmuch as it requires us to as- 
sume some curious laws to be acting in connec- 
tion TOth the sun's atmosphere. On earth it is 
impossible to produce a permanent hole in 
water, and it is equally as difficult to form a 
hole in the atmosphere. Unless, therefore, we 
assume that the sun's atmosphere is sohd, it is 
doubtful whether a permanent hole could be 
produced in it. And thus we have to assume 
an atmosphere of a particular nature before we 
can imagine any holes to be made in it. 

Dming the evenings of March and April, 
and before smirise in October, there appears 
sometimes a faint luminous cone of light near 
the sun, which in appearance is not unlike the 
tail of a comet. In these latitudes this phe- 
nomenon, called the zodiacal light, is not so 
often seen as it is in equatorial regions. It 
has been remarked, that when the sun is free 
from spots the zodiacal light is rarely seen, but 
when the opposite condition prevails, then the 

D 



34 COMMON SIGHTS 

light is frequently observed. The colour is 
usually of a rose-pink, and it varies in in- 
tensity according to the state of the atmo- 
sphere. 

It is impossible to avoid feeling grateful to 
the great Euler of the universe, when we realize 
the vast enlightenment which has taken place 
in the human mind since the earliest ages of 
man. We can scarcely bring before us any 
example which so completely exempHfies this 
fact as that connected with the present know- 
ledge of the movements of the heavenly bodies. 

In the olden times, centuries before England 
was anything greater than the residence of bar- 
barians, the movements of the celestial bodies 
had occupied the attention of the Eastern 
sages; but in too many instances the slight 
knowledge which they did possess, was trea- 
sured merely because it enabled the possessors 
to wield an influence over the ignorant and 
bigoted. 

An eclipse of the sun, which can now be 
predicted years in advance, and wdthin a minute 



IX THE HEAYEXS. 35 

of the time of its occurrence, was in the olden 
time a cause of fear and dread, and was made 
use of as an excuse for sacrificing victims to 
superstitious bigotry, or for the purpose of 
extorting obedience from an alarmed and igno- 
rant public. 

Those who have studied the history of even 
modern progress, and have seen how in a com- 
paratively enlightened age innovations have 
been scouted, and great truths rejected and 
abused for years, or until the facts became too 
powerful to be denied, can imagine what must 
have been the fmy and astonishment of those 
antiquated savants who had long taught astro- 
nomy and astrology, when it was first an- 
nounced that a solar eclipse was caused by the 
intervention of the dark body of the moon. 
This assertion was so utterly at variance with 
that which was in the earliest ages called real 
orthodox science, that it merely excited the 
anger or ridicule of the hearers. 

There appears to be tolerably good evidence 
to show, that the Chaldeans were able to foretell 



36 COMMON SIGHTS 

with some certainty both eclipses of the moon 
and of the sun ; yet when Anaxagoras the 
Greek announced that it was the moon which 
caused a solar eclipse, his assertion brought 
upon him the censure of his countrymen, and 
he was banished as an infidel. 

To most modern minds the explanation of an 
eclipse appears so simple, that we wonder how 
any other cause could for a moment have been 
accepted. Yet when the mind has from child- 
hood been taught that certain effects are due to 
such and such causes, it is very difficult to up- 
root this teaching, though to the unprejudiced 
it may appear absurd and unnatural. 

It must have indeed been a hard trial for 
the advanced men of the early ages, who, having 
patiently thought and carefully observed, at 
length wished to explain the cause of eclipses. 
The hearers were so different from a modern 
audience, that we can only imagine their state 
if we have witnessed the unreasonable pro- 
ceedings of some half-savages, upon whom 
logic, argument, demonstration, or facts would 



IN THE HEAVENS. 37 

produce no more effect than the same weapons 
upon a herd of swine. Yet what must have 
been the inward feeling of those few leading 
minds who had read aright the page of nature ? 
Observing in some solitary tower, the astro- 
nomer must have felt himself almost in an- 
other world as he found his reasoning true, and 
his calculations connected with the period of 
an eclipse verified by facts. Still, as in all 
cases, a price must be paid for the possession of 
knowledge ; and this solitary student of the 
heavens must at times have felt lonely, and 
must have thirsted for a few kindred and ex- 
panded minds with which to exchange ideas ; 
for the more elevated become our thoughts the 
more do we contract the circle of our boon 
companions. 

An eclipse of the sun is a sufficiently rare 
phenomenon to excite universal attention. To 
astronomers an eclipse becomes interesting in 
consequence of its being the means whereby 
they may correct any errors which exist in tlie 
calculated positions of the sun and moon ; for 



38 COMMON SIGHTS 

although the principal moyements of these two 
bodies are now well known, still there are some 
minor changes which occur, and which from 
time to time require that corrections should be 
made. 

The first object observed in a solar eclipse is 
that the sun has lost its circular form, and 
appears to have a chip taken out of his western 
side. This chip becomes larger and larger, 
and as it does so the sunlight becomes dim, and 
the landscape is seen by means of an unnatural 
pale-yellow light. According as the eclipse is 
partial or total, and according as the moon 
passes across the upper or lower portion of the 
sun, so will the commencement of the ecKpse 
produce a variety of appearances. When the 
eclipse is at its maximum the sun may be 
entirely obscured, or may appear as a ring of 
light, according as the echpse occurs when the 
moon is at the least or greatest distance from 
the earth. 

It is when the sun is almost entirely obscured 
that some singular appearances have been ob- 



IN" THE HEAVENS. 39 

served at the extremities of the moon. The 
first of these consists of a number of pro- 
tuberances, or prominences, which become 
visible on various parts of the extremities of 
the moon. These are sometimes of a lake-red 
colour, sometimes bright red, and at other 
times nearly white. The sketch, Plate 3, shows 
the general appearance of these protuberances. 

Several theories have been invented to ac- 
count for the observed facts, but, like the spots, 
all is as yet mere speculation. Some observers 
have supposed that the red flames have been 
seen just where there was a large spot on the 
sun; but it as often happens that where no 
spots exist there the flames are visible. From 
careful observations which have been made 
since 1842, it is probable that the appearance 
results from some condition existing on the sun, 
and is not due to anything on the surface of 
the moon : thus probably they . are merely 
material objects, perhaps similar to clouds in 
our atmosphere. 

The moon is surrounded during a solar eclipse 



40 COMMON SIGHTS 

with a luminous ring, which gives to it a very 
beautiful appearance. Dr. Halley, speaking of 
this, says, in reference to an eclipse in 1715 : 
" Some seconds before the sun was entirely 
hidden there appeared a luminous ring around 
the moon, in breadth equal to a twelfth, or 
perhaps even a tenth of the moon's diameter. 
Its tint was a pale white, or we may say a 
pearly white ; it appeared to me to be slightly 
tinted with iridescent colours." Speculation is 
still busy in assigning a cause for this appear- 
ance as well as the former. During future 
eclipses, amateurs may consider both these 
phenomena worthy of observation. 

We will consider more fully those movements 
of the earth and moon which cause eclipses 
when we speak of the moon. 

Eclipses have happened at various remark- 
able periods, and consequently amongst an 
ignorant and superstitious race they have been 
regarded as objects of fear. During my resi- 
dence on the south-eastern coast of Africa an 
eclipse of the sun happened, and which I had 



P1.3. 



Partial and Total Eclipses of tlie Sim . 




TinDsnt BxookiiJi 



The Ted flaraes during Eclipses. 



IN THE HEAVENS. 41 

announced to some of my Ka£6r companions. 
They were very incredulous that ''the sun 
would be ill/' until they saw its light begin to 
decrease, when they were greatly astonished. 
Theii* inquiries were original and amusing ; 
some of the men asking why the sun was not 
well, others wishing to know whether it was 
tired, and thought it time to lie down behind 
the hills. When they received an explanation, 
and were told that in a few days the moon would 
l>e seen, and that it was her passing before the 
sun that caused the eclipse, they mostly com- 
prehended the cause at once ; and one man 
added in explanation to his hearers that the 
line of shadow luas cuiwed like the moon. 

Thucydides states that there was an ecKpse 
of the sun during the first Peloponnesian war ; 
and Plutarch informs us that Pericles had some 
difficulty in persuading the men who were 
on board his galley to accompany him, as they 
feared that the sun becoming dark was an evil 
omen. The o'reat battle of Arbela was fou2:ht 
eleven days after an eclipse, and thus the date 



42 



COMMON SIGHTS 



of the battle becomes known by a reference to 
the lunar and solar tables. The following are 
the lyrincipal eclipses of the sun which will 
be visible in England during the next forty 
years : — 

1865 October 19th.... 4 p.m. 

1867 March 6th 8 a.m. 

1870 December 22nd . . 11 a.m. 

1874 October 10th. ... 9 a.m. 

1887 August 19th 3 a.m. 

1900 May 28th 3 p.m. 

There will be other eclipses visible, but 
merely very partial ones. 



IJJ THE HEAVEXS. 43 



CHAPTER III. 

"What song the Syrens sung, and what name Achilles 
assumed when he hid himself among women, although 
puzzling questions, are not beyond all conjecture." 

From the region of facts we pass to that of 
conjectare, and we will now consider the pro- 
bable condition of our central orb. 

It is frequently considered a sign of mental 
weakness to deal with speculations, whilst to 
collect facts is a proof of sound sense. To 
speculate when we have no grounds upon which 
to build is certainly injudicious; but to com- 
pare probabilities, and to reflect upon the 
evidence, or upon the condition of the unknown, 
is a proceeding not unlikely to lead to the dis- 
covery of truth. 

Sometimes we find that individuals have 
been designated speculators, simply because 



44 COMMON SIGHTS 

they differed from the speculations of those 
who had preceded them, and who imagined that 
their theory or speculation must rest upon in- 
controvertible facts. Thus we usually find that 
the sound, close reasoners of the early ages 
w^ere designated by certain men visionaries and 
speculators, whereas these characteristics in 
reality belonged to those who believed their 
positions secure and immutable. 

The earliest scientific men speculated upon 
the form of the earth ; they agreed that it was 
flat, and that it rested upon water. Those 
who at a later period disagreed with this hy- 
pothesis, and believed that the sphere was the 
more true form, were regarded as speculators 
and visionaries, with whom it was useless to 
reason. 

In quite modern times the geologist was 
looked upon as a visionary, and who, like 
Galileo, was accused of an attempt to disprove 
Scripture. Now, however, when men's minds 
are more enlightened, it is found that these 
very facts revealed by geology prove more 



IN THE HEAVENS. 45 

than ever that an all-powerful Creator, whose 
wisdom is unbounded, must have made the 
earth and all it contains upon a prearranged 
system. 

It is almost impossible to name any subject 
upon wliich there have not been some opinions 
formed: when, therefore, we speculate upon 
these subjects, and come to a different con- 
clusion to that previously arrived at, it is 
merely one idea opposed to another, and we 
must then consider the probabilities affecting 
each. 

Thus a speculation upon the unknown should 
not be widely or gratuitously condemned, more 
especially when certain notions are accepted 
as true, and which are in themselves merely 
speculations. The cause of the sun's heat is a 
subject w^hich must possess considerable interest, 
but which is one coming within the bounds of 
speculation only. We have therefore to con- 
sider the probabilities connected with the cause 
of this heat ; and as a preliminary step we may 
reflect upon some of the various methods at 



46 COMMON SIGHTS 

present known, and by means of which heat is 
produced. 

First we have the common method — viz., by 
means of fire. It is here necessary that some 
description of fuel should be supplied, and we 
are not aware of any means by which a great 
fire can be maintained except by the aid of 
fuel. 

Secondly. Heat may be produced by means 
of friction, and according to the conditions 
under which this friction takes place, so the 
heat evolved is great or otherwise. 

Thirdly. Great heat is produced in many 
substances when a current of electricity is 
passed through them : thus platinum, silver, 
and substances in which sulphur is contained, 
will usually become very hot v*hen they are 
employed as conductors. 

Fourthly. During many chemical changes 
great heat is produced and evolved by certain 
combinations in various substances. 

These are all simple methods of producing 
heat ; how many more ways there may be it is 



IN THE HEAVENS. 47 

impossible to say, although it is probable that 
there are many more, for it is not likely that 
we have just now reached the end of discovery 
connected with heat. 

We may next consider the various facts con- 
nected with the heat of the sun ; and amongst 
others we find that when the sun is nearly 
vertical we feel more heat than when he is near 
the horizon ; that if we ascend to the summit 
of lofty mountains we obtain less heat, although 
the sun may be directly overhead. Even from 
these two facts we are taught that the heat of 
the sun is dependent in a great measure upon 
the state of the atmosphere through which the 
rays pass, and upon the angle which these rays 
make with the earth's surface. 

There is no evidence which should induce us 
to think that the sun is a great fire, or that it 
is in itself any hotter than is our earth. The 
particles of which the sun is composed may be 
charged with, or they may be producing great 
quantities of a subtle force somewhat similar to 
electricity. This force, or power, may produce 



48 COMMON SIGHTS 

no effect on space, but when it enters an atmo- 
sphere it may at once produce heat and light. 
We know that a gun may be fired by means of 
electricity, although it may be at the distance 
of twenty or thu^ty miles from the battery. 
The battery itself is quite cool, and so is the 
copper wire which conducts the electricity. 
When, however, this subtle current traverses a 
piece of platinum wire, the wire instantly 
becomes red hot, and the gun can be fired. If 
a person w^ere ignorant of the law that the heat 
induced in any substance by the transmission 
of an electric current was dependent on the 
conducting power of the substance, he might 
imagine that the battery itself must be at a 
fearful heat in consequence of the wire twenty 
miles distant becoming red hot. 

Hence it is not improbable that our great 
central orb may be a cool summer residence, but 
possessed of a power which is not (at least yet) 
manifested by the various planets in the system. 

It is not improbable that according to the 
atmospheric or other condition of a planet, so 



IX THE HEAYEXS. 49 

may it be able to gain great or little heat from 
a certain quantity of the sun's rays. 

It is absurd to build any theories upon the 
supposition that because a planet is at a great 
distance from the sun, that therefore it must be 
very cold, and vice versa. We may be sure that 
the architect of the universe made some ar- 
rangements to overcome this, to us, apparent 
difficulty. 

The planet Jupiter is far brighter and appears 
even better hghted than does the planet 3Iars : 
and yet the former is not so near to us as is 
the latter by about three hundred and forty 
million miles, and Jupiter is rather more than 
that number of miles farther from the sun than 
is Mars. 

It would be indeed singular if om- little earth 
were the only orb in the system with a climate 
suitable to what we know of organic life. 
When, however, we consider that the heat de- 
rived from the sun may be dependent upon the 
condition of a planet's atmosphere, we see no 
difficulties in our way. 

E 



50 COMMON SIGHTS 

Another singular fact which is interestmg is 
that the sun rotates upon its axis. 

To assert that any great work of nature is 
not made for some definite purpose is very like 
an endeayour to libel creation. Surely, then, 
this rotation must be for a purpose ; what that 
may be is a subject for conjecture. 

Upon observing the different members of the 
solar system w^e find that they all move round 
the sun and in the same direction, the sun 
itself rotating in the same way as the planets 
revolye. Thus the yarious ^^lanets seem to roll 
round their orbits, and in the same dh^ection 
that the sun itself rotates. The rotation of the 
sun appearing to carry the planets onwards in 
then- course. That which is yery remarkable is, 
that just as the sun appears to turn the yarious 
planets around him, so do the yarious planets 
turn their satellites around them. 

If now we consider the improbability of eight 
primary planets, about sixty smaller planets, 
and upwards of a dozen satellites all follow- 
ing this rule ly chance^ we at once perceiye 



IN THE HEAYEXS. 



51 



that these movements must be obedient to a 
law. 

The following diagram will explain the joint 
movement of the sun and a planet, and will also 
show a curious fact connected with the earth's 




movement and the distance of the moon. S 
represents the sun, which turns round from 
A to B. M N is the earth's direction of 
movement. 

If now we suppose E the earth, about which 



52 COMMON SIGHTS 

a circle is described with a radius of about two 
hundred and forty-five thousand miles, and then 
cause this circle to roll like a wheel around 
M N, then the earth would turn round 
just as often as it does every year, to perform 
its annual course : the radius of the small cu'cle 
is nearly the mean distance of the moon from the 
centre of the earth. Thus if we considered the 
earth the nave, and the moon's orbit the tire of 
a wheel, then this wheel would roll around the 
sun at their present distances, in as nearly as 
possible 365 days. 

From the experiments of various philosophers 
it has been shown that, when a magnet is made 
to rotate upon its axis, it will cause many sub- 
stances near it, as well as gases, to rotate also. 
It is not necessary that the substances should 
be themselves perceptibly magnetic; for clay 
and wood have been found to be thus in- 
fluenced. May it not be possible that the 
rotation of the sun causes in some way the 
rotation of the various planets ? and may we 
not have become acquainted with an effect only. 



IX THE HEAYEXS. 53 

when we speak of grayity. and the haws of 
gravity ? The mdiyidiial who observed the 
effect of an electro-magnet,, might possibly at 
fii'st overlook the fact that the battery was the 
instrnment as well worthy of study as the piece 
of iron which attr-acted the various metals placed 
near it : for the more we can trace effects to 
other effects, the nearer we must be to causes. 

The Sim is spherical, and rotates upon an 
axis, and thus bears a strong likeness to the 
planets. A Cjuestion which naturally arises 
here is, whether the sun is entirely independent 
as regards its source of heat-giving power ; or 
is it connected by some subtle means vith 
another orb? Is the sun, in fact, a planet 
to some other sun ? and is our eaith, and are 
the other planets, but the satellites of our 
sun ? 

Vre have seen that there is good reason to 
beheve that the spots on the sim produce some 
effects of a magnetic and electric character 
upon our earth ; and we are by this fact pre- 
pared to believe that there are agencies at 



54 COMMON SIGHTS 

work in the universe of a subtlety and power 
beyond our present knowledge or experience. 
Thus the sun may be influenced in a measure 
by some distant twinkling star, which is yet 
a mysterious link between our sun and other 
portions of creation. 

If there were an inhabitant on one of Nep- 
tune's satellites, he might not think much of 
the influence of our sun upon his primary 
planet,. and he might be sadly puzzled to ac- 
count for the variations in light and darkness 
which occurred. 

Some observers have supposed that the two 
hemispheres of the sun do not give an equal 
quantity of light. If this behef be a truth, it 
would give some probability to the supposition 
that the sun is not entirely independent ; for 
we might conclude that there was a summer 
and a winter on the sun, and thus that one 
hemisphere (the brightest) was then enjoying 
summer, and the other possessing winter. 



P1.4. 




'Vjnr^.nt, BrO olcs ,llth . 



THE MOOIS^ 
SIX DAYS OLD. 



IN THE HEAYEXS. 55 



CHAPTEE IV. 



THE MOOX. 



Next to the suu, the moon is the celestial 
object which attracts the greatest attention. 
From the earliest ages the moon has been con- 
sidered a mysterious body ; wielding influences 
over men's minds, and over the weather, and 
causing strange vagaries to be played by the 
otherwise orderly course of nature. 

It is not at all surprising that the moon 
should have been considered mysterious in an 
age when mystery was preferred to simplicity ; 
for her movements and condition, even in the 
present age, are subjects about which some un- 
certainty exists. 

To the casual observer, the moon's changes 
and movements appear hopelessly intricate ; 
but when we obtain a key to these, we find that 



56 COMMON SIGHTS 

simplicity takes the place of apparent con- 
fusion ; and that the lunar machinery, like all 
Nature's works, is arranged upon the most 
beautiful and orderly system. 

The moon first appears like a thin crescent, 
and close to the sun. The side nearest to the 
sun is that which is illuminated. Soon after 
the sun has set the moon also disappears beneath 
that portion of the horizon near where the sun 
set. 

If the evening be fine and clear, not only 
will the thin bright crescent of the moon be 
visible, but also the whole round body, which 
appears of a pale-yellowish tint, and somewhat 
smaller than the bright crescent. 

The moon is a body which gives out little or 
no light from itself, but merely looks bright in 
consequence of its reflecting the sun's light. 
Thus, when it appears in the heavens as a thin 
crescent, this appearance arises from the greater 
part of the sun-lighted portion of the moon 
being invisible to us. 

The paler light of the remaining portion of 



IX THE HEAVENS. 57 

the moon is due to the reflected light of the 
earth, which then shines on the moon just as 
does the full moon upon the earth. 

We must remember that, when a ball is 
shone upon, half the surface of that ball will 
always be lighted ; and, just as we stand with 
reference to the ball, so can we see the lighted 
portion as a thin crescent, a semicircle, or a 
circle. 

When we see the moon as a thin crescent, 
that part upon which the sun shines is only 
partly turned towards us, and the earth, the 
moon, and the sun are nearly in the same 
straight line. 

If we watch the new moon, we shall find that 
each night the crescent will appear larger and 
larger, until the bright portion is of a semi- 
circular shape. During these changes it will be 
found that the moon moves farther from the 
sun each night ; and, instead of setting imme- 
diately after the sun, as was the case when she 
was in the thin crescent form, she will now be 
nearly to the south when the sun is in the west. 



58 COMMON SIGHTS 

When the moon is half enlightened, or rather 
when we see the half of the lighted part of the 
moon, then a line drawn from the sun to the 
moon vrill be at right angles to one drawn from 
the moon to the earth. 

The ancient astronomers were aware of this 
fact, and they suggested a yery ingenious 
method for determining the relative distance 
from the earth of the moon and the sun. 

They- Avatched until the moon appeared an 
exact semicircle : they then measured the 
number of degrees between the moon and the 
sun, and they thus had a right-angled triangle, 
as follows : — 




M was the moon, E the earth, and S the sun. 
The anoie S M E they knew must be a rio-ht 
angle ; the angle M E S they measured, and 
consequently they knew^ the proportional dis- 



m THE HExiYENS. 59 

tance of M E and E S ; for the three angles 
of any plane triangle make 180^. Thus they 
could find the angle M S E. Then by rule of 
three — 

As the sine of the anole M S E 

Was to the distance M E, 

So was the sine of the angle EMS 

To the side E S ; 
and thus the proportion between M E, the 
moon's distance, and E S, the sun's distance, 
became known. 

There is sometimes a great difference between 
theory and practice, and so it proved with this 
problem ; for the ancients came to very dif- 
ferent conclusions, in connection with the re- 
lative distances of the sun and moon, from those 
which are accepted in the present day. The 
idea nevertheless was ingenious, however un- 
certain were the practical results. 

The enlightened portion of the moon will 
each night appear larger and larger, and she 
will move farther from the sun, until she is 
quite circular. At this period the earth, moon, 



60 COMMON SIGHTS 

and sun are in a straight line, the moon being 
on one side of the earth, the sun on the other. 

When the moon is full, she rises at nearly 
the same time that the sun sets, and sets at the 
same time that the sun rises. 

The same changes take place duiing the 
decrease in apparent size of the moon that 
occurred during her increase, except that it 
will be the eastern side that is now illuminated, 
instead of the western. So that, if we stand 
facing the moon, we shall see the right-hand 
side illuminated dm^ing the time that she in- 
creases in brightness, and the left-hand side 
when she is decreasing. 

Just before sum^ise we may observe the moon 
like a thin crescent, just as we see her at times 
after sunset when she is new, the opposite side 
being now bright. 

The moon, like the sun, sometimes appears 
of a large size on the horizon, and of a deep 
red tint, and her colour and brilliancy vary 
considerably. These effects are most probably 
due to changes in the atmosphere of the earth. 



IX THE HEAVEXS. 61 

When we know that it is the sun that causes 
the moon to seem bright, there is an appear- 
ance in the moon which at first sight is para- 
doxical. This is, that if we draw a straight 
line from the sun to the moon, the illuminated 
part of the latter does not at all times appear 
at right angles to the former, as it ought to do. 
This becomes most apparent when the moon is 
about half full, and is about south-east when 
the sun is south-west. The following sketch 
will show the appearance referred to. 

MOOx 



^^&ru, Eo rizon . 



^^^ 



This is due to the horizon being aiwarently 
a straight line, whereas it is really a curve ; 
and as we refer the line between the light and 
darkness on the moon to the horizon, this line 
appears not to be perpendicular to the former. 

All the celestial bodies appear to describe 



62 COMMON SIGHTS 

circles in the lieayens, altliongh they may re- 
main stationary ; and thus any 'portion of the 
apparent course of a celestial body appears to 
be part of a circle. 

If the moon, instead of being a spherical 
body, were a long attenuated body, she would 
appear in the heavens like a bow. We can 
easily see how this would be, if we observe 
where the moon rises, and where she is at 
various times during the night. Then, if she 
were a long thin body, the various portions 
would extend in a curve from the eastern 
horizon to nearlv the south, much in the man- 
ner shown below. 




1, 2, 3, 4, here represent the various positions 
of the moon at different times during the night. 
Then, if the moon were a long thin body, it 
would appear as sho^m by the Kne 1, 2, 3, 4. 



IX THE HEAYEXS. 63 

This is the reason why the tails of comets 
most frequently appear curved.* If, however, a 
person were in the central portion of the earth 
when the moon passed dhectly overhead, this 
same line vrould appear to be straight, just as a 
bow would appear straight if held with the bow- 
string towards us. Thus a comet's tail might 
appear bent to an observer in the northern or 
southern portions of the earth, but quite straight 
to an observer near the central latitudes. The 
bendmg being dependent upon the direction of 
the comet's tail in the heavens in connection 
with the horizon. 

If the moon be observed dining several 
nights, it will be seen that her height above 
the horizon varies considerably^ Sometimes 

"^ It has been remarked by several observers that the tail 
of the great comet of 1861 Tvas straight, and that this was a 
peculiarity. The fact was that the appearance was dne to 
the position of the tail, which extended from ithe horizon to 
the zenith. K the tail had extended from east to west and 
over the equator, then to an observer in the north or south 
the tail would appear curved ; but if the tail were near the 
zenith — /. e., if an observer were at the equator, it would at 
the same time seem to him quite sti'aight. 



64 COMMON SIGHTS 

slie rises and passes to the south with a less 
altitude than the sun has durins: midwinter. 
Then, in less than a fortnight, she will pass 
to the south with a greater height than has 
the sun duiing summer. 

The reason of this is, that the moon moves 
around the earth in about 27i ; days and thus, 
durmg the half of that period, a change in the 
altitude of the moon takes place, just in the 
same ihanner as a change in the sun's altitude 
occurs in six months. The following figure 
may aid to explain this fact. 




^4r 
E represents the earth ; the direction of the 
north pole of w4iich is indicated in the sketch. 
A and B are two positions of the same observer 
on the earth's surface ; x and y represent two 
positions of the moon, so that, if x be the 
moon's place on any day, then fourteen days 



IN THE HEAVENS. 65 

afterwards the moon will be in the position 
shown by y. 

To the observer when at B, the moon will 
appear very low down, and near the horizon ; 
but when he is at A, and the moon at y^ then 
she will appear nearly over his head. 

There are several other changes which occur 
in the apparent height of the moon, but these 
are beyond the range of the present book. 

We remarked that the moon moved round 
the earth in about 27^ days. This, however, is 
not the interval between two full moons or two 
new moons, &c. The period between two full 
moons is about 291 days. This difference 
arises from the fact that, wliilst the moon 
moves round the earth, the earth moves round 
the sun. If the earth stood still, then the 
moon would become full at intervals of 27^ 
days. 

Thus, in the following sketch, S is the sun, 
E the earth, and M N three positions of the 
moon, which at M is full, at half full, and at 
N invisible. If the earth remained at E, and 

F 



66 COMMON SIGHTS 

the moon moved round from 31 to and to X, 
then the interyals between the Ml moons would 



be just equal to the time of the moon's passage 
round the earth. 

If, however (as is the case), the earth moves 
on to V, then the moon will have moved round 
the earth, and will have reached to Q in 27-^ 
days, but she wdll have to move on to R before 
she appears '' full," and it occupies her rather 
more than two days to move from Q to E. 

The shorter of these two j)eriods is called the 
sidereal revolution of the moon, the longer the 
synodic revolution. 



IN THE HEAYEXS. 67 

In consequence of the earth turning round 
on its axis, we have an alternation of day and 
night ; and if there were an observer on the 
sun, every portion of the eartli would be visible 
to him once in twenty-four hours. The moon 
does not turn upon her axis in the same manner 
as does the earth, for only about one half of the 
moon has ever been seen by man. This arises 
from the fact that the moon turns round in 
exactly the same time that she moves roimd the 
earth. 

If we were to stick a sword into a large 
apple, hold the sword with the apple on the 
point at arm's length, and then move the sword 
around us, we should only observe one half of 
the apple, and the apple itself would not spin 
upon its axis like a top. Just so is it with the 
moon, which always turns one face towards our 
earth. 

In consequence of the moon revolving round 
the earth, she is of course lighted on all sides 
by the sun, and thus during about twenty-nine 
and a half of our davs the moon has one dav 



68 COMMON SIGHTS 

and a night, so that her day is rather longer 
than fourteen of our own. 

If our earth were to move in a similar manner 
to the moon, only a little more than one half of 
the earth would ever see the sun, whilst the re- 
mainder would be in darkness, and thus there 
would be no evening and morning, and no 
alternation of day and night. 

Some singular ideas are forced upon us when 
we consider this subject, and find that in the 
Mosaic account of the earth's earlier histories, 
there was a period when there was darkness 
upon the face of the deep, for it appears by 
this, that the evening was, and the morning- 
was, aftei^ the first condition. It would be sin- 
gular if in the vast ages to come the terrestrial 
inhabitants were to find the moon bestirring 
herself, and turning on her axis like the earth. 
Yet this change cannot be pronounced impos- 
sible, in consequence of our utter inabihty to 
explain the cause of the rotation of a single 
planet in the system. 

The moon follows the same law in her revo- 



IN THE HEAVENS. 69 

lution that the various planets follow ; viz., she 
moves round the earth in the same direction 
that the earth rotates : thus the earth appears 
as it were to drag the moon round her, just as 
the sun appears by his rotation to drag the 
planets around him. 

The moon, when examined with the naked 
eye, appears to present a smooth and regular 
surface. There are dark patches in various 
parts, which assume the form of a man's face, 
but there does not seem to be any great irre- 
gularities on the moon itself. When, however, 
we direct a telescope of moderate power to- 
wards the moon, a strange scene is presented 
to us; the curious face-like appearance disap- 
pears, and we observe a collection of light and 
dark patches, streaks of light or shade, circular 
lines, and all the varieties of a volcanic and 
mountainous district on earth. 

That portion of the moon which borders on 
the dark part is covered with long shadows, 
whilst here and there brilliant peaks shine 
against the dark background. Occasionally 



70 COMMON SIGHTS 

two or three star-like objects become visible 
near the borders of the enlightened portions 
of the moon, as the sunlight is reflected from 
the most lofty mountain summits, which are 
illuminated before the less eleyated localities 
near them. Huge craters and long ravines, 
gentle slopes and clusters of mountains, all 
become visible with the aid of the telescope- 
The appearance presented by the moon's sur- 
face is like that of a vast volcanic district, 
where igneous action has only just ceased, and 
where the forces at work have been much 
greater than upon our earth. Some of the 
largest craters on earth are not one tenth 
as large as those on the moon. Thus Tene- 
riflfe scarcely exceeds nine miles in dia- 
meter, whereas a crater in the moon called 
Clavius measures about one hundred and forty 
miles. 

Some of these lunar craters are circular, 
whilst others are very much elongated. They 
are best seen when the moon is only partially 
lighted by the sun, and when consequently the 



IN THE HEAYEXS. il 

sides of the crater cast shadows upon the siir- 
roundino: hollow ofroimd. 

Mountains and yalleys, hills and dales, are 
observed on the moon ; but there does not 
appear to be any indication of large seas, or 
even water. Eecent observations have led to 
the belief that there is vegetation on the moon, 
at least at times, but this statement requhes 
confirmation. 

It is very easy to see, tiiat if we know the 
length of shadow which an object casts, and 
the angular position of the light, that we can 
ascertain the height of the object. This fact 
has led to the investigation of the heights of 
the mountains in the moon; and some very 
elaborate tables have been constructed, sho^^dng 
the altitude of the various mountains. 

There is, however, very little dependence to 
be placed upon these conclusions, however in- 
genious they may be, for it does not in the 
least follow that the hiohest mountaiDs should 

o 

cast the longest shadows ; and the various 
altitudes assumed for the lunar mountains 



72 COMMON SIGHTS 

are calculated upon the supposition that they 
do. 

For instance, upon earth the Himalaya 
mountains are the highest. These mountains 
are not very abrupt in parts, but they slope 
gradually upwards, and therefore they would 
not, with the sun in any position, cast a very 
great shadow. And if we observed the earth 
from the moon, the Table Mountain, which 
rises abruptly, would cast a longer shadow than 
the Himalaya mountains, and w^ould therefore, 
upon the above assumption, be supposed much 
higher, whereas in reality it is not one-sixth 
the height. 

The length of shadow cast by a lunar moun- 
tain will merely give the elevation of that 
mountain above the surface immediately around 
it, but it will not give the relative altitude of 
the various mountains above a fixed datum. 

When we consider the preceding reasoning, 
it induces us to believe that the mountains in the 
moon are much higher than any on the earth, 
for some of the elevated peaks are found to be 



IN THE HEAVENS. 73 

nearly twenty-fiye tliousand feet above the sur- 
face in tlieii' immediate neighbom^hood, and 
thus they may be several thousand feet more 
above the lowest gTOund. 

If it be a fact that the moon is not possessed 
of any seas or lakes, it appears only in accord- 
ance with terrestrial conditions that there 
should be yerj great irregularities on her sur- 
face ; for if the earth had no sea there would 
be some deep ravines and mighty peaks ex- 
posed to view in various places where the ocean 
now exists. 

The outline of the moon is somewhat jagged 
and irregular, but not to so great an extent as 
might be at first supposed. The approach to 
uniformity arises from the fact before men- 
tioned, that we should merely observe the pro- 
jection of certain peaks beyond the surrounding 
ground, and thus, although there would be 
irregularities in the outline, still these would 
not be so very marked. 

The surface of the moon appears to have 
been considerably disturbed, and torn by various 



74 COMMON SIGHTS 

forces. The deep craters at once show this. 
There is, however, another action apparently at 
work, and which produces stars and rents, just 
as when the ice has been broken by a skater. 
These flaws appear to indicate that there has 
been, or is, some upheaving force going on in 
the lower strata of the moon, and which causes 
the surface to crack and separate at the lines 
of least resistance. In fact, there would be in 
the moon numerous flaws in the strata similar to 
the " faults " in the lower deposits of our earth. 
We have not to search far before we find a 
probable cause for the highly volcanic con- 
dition of the moon's surface. Any traveller 
v>^ho has passed a day upon the burning plains 
in tropical regions, when the sun at midday is 
in his zenith, and when he is exposed to the 
sun's rays only twelve or fourteen hours, can 
imagine the state in which the soil and air would 
be were the sun to remain twelve or fourteen 
days above the horizon. This is the condition 
of each portion of the moon's surface, which is 
exposed during about a fortnight to the con- 



IX THE HEAYEXS. 75 

tinued rays of the sun, and then, during a like 
period, the sun is invisible. 

It is only reasonable to suppose that what- 
ever may be the condition of the lunar atmo- 
sphere, and the other agencies appertaining to 
her, still the sun causes heat upon her surface, 
and during his absence there must be cold. A 
very great alternation of climate, therefore, 
occurs upon the moon during every month, 
heat and cold being both very intense : and 
these great changes, and the long-continued 
action of the sun, it is highly probable would 
produce volcanic action, especially if just be- 
neath the lunar surface there are rocks con- 
taining sulphur, or other non-conducting matter. 

It has long been a subject of discussion 
whether there are any volcanoes now burning 
in the moon. Some observers have come to 
the conclusion that they have seen luminous 
points, which could not be accounted for in 
any other way than by supposing these to be 
active volcanoes. Other observers deny that 
there is any evidence to prove that volcanoes 



76 COMMON SIGHTS 

are at present active, and that which indi- 
viduals have supposed to be a volcano, was 
merely an illuminated peak. 

In controversies of this description it must be 
borne in mind that no amount of negative 
evidence is sufficient to disprove one fact, and 
thus if half a dozen careful observers have seen 
appearances which may be fairly assumed to 
be active volcanoes, it matters but little whether 
half a hundred individuals have never seen 
anything of the kind. It certainly appears 
reasonable to suppose that there is igneous 
action going on upon the moon's surface, when 
we consider her appearance, and the amount of 
sun heat to which she is exposed. We ought to 
look for active volcanoes after the moon is full, 
as she has then been exposed to a continuance 
of sunlight for a long period : thus when the 
moon is south, at about 2 or 3 o'clock a.m., is 
the best time. 

If there be any very great changes occurring 
upon the moon's surface, these ought in the 
course of a few years to be discovered. Photo- 



IN THE HEAVENS. 77 

graphy is an artist who neither flatters nor tells 
falsehoods, and now that a photograph of the 
moon can be taken, and when this photograph 
can be placed under a microscope, we may col- 
lect a variety of lunar portraits, which, handed 
down to posterity, may serve to clear up this 
otherwise questionable problem connected with 
the geology of the moon. 

It has been remarked that when the public 
are left to themselves, they will frequently, by 
a sort of intuition, come to correct conclusions 
upon even abstruse subjects. We must, how- 
ever, take care that we do not confound this 
sort of intuition with opinions which are the 
result of a bias being given to public opinion 
by self-elected authorities. 

The earliest almanacs invariably connected a 
change of weather with a change of moon, and 
thus a bias was given to public opinion which 
might not otherwise have expressed itself. 

There is to the loose reasoner something re- 
markably agreeable in the vagueness of the 
terms "change of weather" and "change of 



78 COMMON SIGHTS 

moon." What does change of weather mean ? 
From wet to fine, from fine to wet; from 
cloudy to clear, from clear to cloudy ; from 
damp and foggy to dry and frosty ; from a cold 
north wind to a mild south wind ; from a nip- 
ping east to a soothing west \^ind ; from snow 
to rain, from thmider-storm to calmness ; from 
a hurricane to a gentle breeze — are all changes 
of weather. Then a change of moon, what is 
this ? First, the moon is invisible, then there is 
a new moon. This is a change. Then the 
moon is half lighted, then she is full, then she 
is half-lighted again, then invisible. Thus, 
once a week, the moon '^changes." Now it 
would be indeed strange if some change of 
weather, in some localities, did not occur at or 
about some of the periods when the moon 
changed. 

We have mentioned different localities, and 
this is an important consideration, for if we 
compare the weather in even various parts of 
England, we find but little uniformity at the 
same time. If the climate of Enoiand be com- 



IX THE HEAYEXS. 79 

pared with that of the Continent, still greater 
differences will be found. Which locality, then, 
is to be taken as the one which is affected by 
the change of the moon ? 

In consequence of observations having been 
carried on in various places, different conclu- 
sions have been arrived at by different scien- 
tific men in connection with the influence of the 
moon on the weather. Thus observations car- 
ried on at Stutto-ard and Paris o'ave different 
results from those which were made at Poitevin. 
il. Gasparin found, according to M. Arago, that 
there was the least rain between the full moon 
and the last quarter, whereas at Stuttgard the 
least rain was found at the period of the new 
moon. 

From a consideration of the various facts 
collected by different experimentalists, it ap- 
pears that if the changes of the moon do pro- 
duce any influence upon the weather, the results 
of these influences do not cause so great a 
change, as the local conditions surroundins: 
different places. 



80 COMMON SIGHTS 

We are upon tolerably safe ground when we 
assert that the moon causes some of the tidal 
changes upon earth, and that consequently she 
attracts the waters of the ocean. Granting 
this, we do not find it impossible to believe that 
when the atmosjDhere is imbued with a large 
amount of moisture, that she would attract the 
atmosphere in a manner somewhat analogous to 
that in which she attracts the ocean. When 
we have to consider attraction, we have a very 
subtle force to deal with, and conjecture must 
enter largely into the investigation, whilst posi- 
tive certainties cannot be obtained. Dealing- 
then merely with conjectm^e, it becomes a 
question whether, when the moon thus attracts 
the waters of the ocean or the atmosphere, she 
draws from either any of those elements of 
which water is composed. We find that attrac- 
tion will act at the distance of many millions 
of miles, and it is not, therefore, like any 
material forces with which we can deal. It 
might be then, that when the moon is thus 
attracting the ocean, she is. bv means of the 



IX THE HEAVENS. 81 

subtle chemistry of nature, drawing from it 
some of the elements of which she herself is 
deficient, and thus she may be forming an 
atmosphere, or obtaining moisture which will, 
by the action of the sun's heat, enable her to 
produce an atmosphere. 

This action may be, according to human 
ideas, very slow ; still, if it exist, we should 
find our moon passing from its present hard 
granitic and volcanic state, into a condition 
which would admit of vegetable and animal life 
of a low order being created upon its surface ; 
and thus a geological change would be marked. 
Perhaps also this long sun period of fourteen 
days might, when the moon possessed an atmo- 
sphere, be suitable for the growth of plants 
which did not produce hard wood ; and thus 
ferns would predominate, which would cease to 
live immediately the sun ceased to shine upon 
them. Their fall would be probably attended 
by a deposit of snow, which another long day 
would melt, and thus growth of ferns might 
follow growth of ferns, and layer after layer of 



82 COMMON SIGHTS 

vegetables might be deposited, which would 
eventually perhaps become the coal beds for 
those who were created upon the moon, when 
its youth had advanced towards maturity. 

In the absence of certainty we can only deal 
with conjecture. 

Another subject of discussion connected with 
the moon is, whether or not she possesses an 
atmosphere similar to the earth. There is 
reason to believe that if the moon possessed an 
atmosphere, then, when any stars passed the 
limbs of the moon, their shape and appearance 
would be considerably altered. As might be 
expected, phenomena of this description have 
been carefully watched ; and there are few in- 
dividuals provided with a telescope of even 
moderate power who have not observed seve- 
ral such transits. Some difference of opinion 
naturally exists as to whether the star or planet 
has shown any variation as the moon passed 
before it ; but the majority of observers agree 
in the belief that no change is produced. It is 
assumed that the atmosphere of the earth does 



IX THE HEAYEXS, 83 

not extend beyond forty-fiye miles from the 
surface ; but this is merely an assumption. An 
atmosphere of a rarefied character may extend 
to any distance. In fact it is difficult to say to 
what extent the earth's atmosphere may ex- 
tend ; and it is possible that the moon may be 
within the radius of the earth's atmosphere ; 
and thus there may be a means whereby her 
volcanoes only smoulder, as it were ; whereas, 
if there were a more dense atmosphere, these 
would burst out into fierce flames. We should 
of course find no alteration in the appearance of 
a star as the moon passed it, if the moon were 
within our atmosphere, unless immediately 
about the moon, the air was much more dense. 
When we observe the incomplete or un- 
finished state of the moon, and then regard the 
present condition of our earth, it is difficult to 
avoid the conclusion that the moon is the 
younger of the two. There is an appearance 
about the moon's surface very similar to that 
which the earth must have presented during 
that early geological period, when granite or 



84 COMMON SIGHTS 

gneiss were the surface soil, and when there 
were not yet conditions sufficiently favourable 
to organic life to admit of the existence of any 
beings of a higher type than a few worms or 
zoophytes. When we consider this probability? 
and when we regard creation from an expansive 
point of view, we are irresistibly struck with 
the singularity of the statement of Lucian and 
Ovid, who both inform us that the Arcadians 
asserted that their forefathers had inhabited 
the earth before it possessed a satellite. Some 
objectors, who are more ready to raise an objec- 
tion than to weigh the soundness of their argu- 
ments, have believed that they had exposed the 
absurdity of this statement when they said, 
*' Then the moon must have been a comet, and 
if so, what has become of its tailT This weak 
objection is so readily answered, that it is sm- 
prising that it was ever urged ; for we might 
remark that the moon, if an old comet, has done 
with its tail, just that which the comet of Encke 
has done with its tail ; for this short-period comet 
exhibits no tail, and when nearest the sun it 



IX THE HEATEXS. 85 

has a diameter not one-tentli of that which it 
has when at its greatest distance. Thus the 
approximation of its particles appears to be 
connected with its distance from the snn ; but 
it does not necessarily follow that the moon was 
a comet : it might have been formed in several 
other ways. 

A statement such as that of Ovid is not to 
be hastily disposed of, either by ridicule or an 
off-hand objection; but probabihties must be 
weighed, and guesses should not take the place 
of facts. 

The distance of the moon is more readily 
obtained than is that of any other c-elestial body, 
in consequence of her nearness to the earth. 
Two locaKties situated in distant parts of the 
world are chosen as points for observation. 
The latitudes of these two stations being kno^m, 
the distance in angular measm^e of the moon, 
from the north pole and fi'om the south pole, 
may be obtained. Thus, if G and C were two 
points upon the earth's surface, such as Green- 
wich and the Cape, then the angTilar chstance 



86 COMMON SIGHTS 

of the moon from the south pole of the heavens, 
added to the angular distance of the moon from 




the north pole of the heavens, will exceed 180'' 
by exactly the angle G M C. 

The distance in miles between G and C is 
known. The two sides M G and M C are so 
nearly equal as not to interfere greatly in the 
question, and thus the angles M G C and M C G 
are known, consequently the sides M C can be 
found by simple trigonometry. 

It will also be evident that to an observer at 
G, the lower portion of the moon might appear 
to just touch a star, wliilst the same star would 
appear at some distance from the moon to an 
observer at C. Hence another means is afforded 
for finding the distance of our satellite, which 
amounts to about two hundred and forty thou- 
sand miles ; a short distance when compared to 



lis THE HEAVEXS. 87 

that of other celestial bodies, but still one suffi- 
ciently great to occupy an express train tra- 
velling at fifty miles an hour, rather more than 
three months to accomplish the journey. 

As soon as the distance of the moon is found, 
her size can be ascertained ; and she is quite 
small when compared to the earth; her diameter 
being only about two thousand one hundred and 
sixty miles. 

An eclipse of the moon lasts a much longer 
time than an eclipse of the sun, first, because 
the earth is larger than the moon, and secondly, 
because when the moon is eclipsed, both she 
and the earth are moving in the same direction, 
but when the sun is eclipsed, then the two are 
travelling in opposite directions. The following 
diagrams will explain this : 

Suppose S the sun and E the earth, which, 
with the moon, is travelling in the direction 
from A to B ; M the moon, during a solar 
eclipse, is travelling round the earth from M 
towards 0, and thus moves in one direction 
whilst the earth is moving in the other. During 



COMMON SIGHTS 



a lunar eclipse, however, the moon will be at Is, 
and will then be moving from N towards P, a 
course which at N is nearly the same as that 



^\o 






F^. 



_M|t 



which the earth follows. Thus the moon re- 
mains some time longer in the earth's shadow, 
and consequently prolongs the lunar eclipse. 

To produce either a lunar or solar eclipse, it 
is evident that the earth, the moon, and the 
sun must be in the same straight line. In con- 
sequence of the moon moving around the earth 
in about twenty-nine and a half days, these 
three bodies must be twice during that period 
in nearly the same straight line. Thus it may 
appear at first sight singular that during every 
twenty-nine and a half days, there should not 



IN THE HEAVENS, 89 

be an eclipse of the sun and moon. The fact 
however is, that the moon only crosses the 
actual path of the sun tvdce during her revolu- 
tion round the earth ; if therefore she does not 
cross this path either when she is full or invi- 
sible, then no eclipse can occur. 

There may be seventy eclipses observed in 
different parts of the world dming a period of 
eighteen years ; of these, forty-one are solar 
eclipses, and the remainder (twenty-nine) are 
lunar. 

In consequence of the proximity of the moon 
to the earth, eclipses of the sun may be seen in 
some parts of the earth as total eclipses, in 
other parts as partial, whilst in others the 
eclipse is invisible. In this respect an eclipse 
of the sun differs from a lunar eclipse. When- 
ever the moon can be seen above the horizon 
during the time of an eclipse, then also the 
phenomenon can be observed ; but it is not so 
with the sun, which, although visible at the 
same instant to two observers, may be partially 
eclipsed to the one but not to the other. The 



90 COMMON SIGHTS 

reason of this may be understood from the fol- 
lowing diagram : 




Suppose S the sun, P the earth, and M the 
moon. An observer standing at upon the 
earth's surface, would see the moon in the 
direction of T, far above the sun ; therefore to 
the locality the sun would not appear to be 
eclipsed. The observer at P, however, would 
see the moon in the direction S ; that is 
directly between him and the sun, which would 
consequently be totally eclipsed. 

As the sun would not be eclipsed to the 
observer at O, whilst it would be totally hidden 
by the moon at the point P, it is evident that if 
observers were placed at various stations be- 
tween P and 0, [they would see the eclipse 



IX THE HEAYEXS. 91 

nearly total, or partial, according as tliev ^Ye^e 
near to P or 0. 

T\lien the moon is eclipsed, the phenomenon 
is due to the earth's shadow, and this shadow 
will not alter its apparent position, although an 
observer may alter his. Thus a total eclipse of 
the moon will be a total eclipse at all places 
where the moon is above the horizon, and a 
partial eclipse ^vill be a partial eclipse. Thus 
there is no necessity to travel to different parts 
of the world to obtain a better view of a lunar, 
although it may be to see a solar echpse. 

If we take any particular locality upon the 
earth's surface, we shall find that more lunar 
eclipses are visible from that locality than there 
are solar, because the duration of a lunar eclipse 
is greater, and it is more likely to be visible 
than is a solar. Taking the whole world, how- 
ever, three eclipses of the sun will occur to two 
of the moon. 

The best time for observing the surface of 
the moon with a telescope is during the first 
quarter. She will then be visible ia the south- 



92 C03IM0N SIGHTS 

western portion of the heavens as soon as the 
evening is sufficiently advanced to enable us to 
see her without difficulty. The sun is then 
shining upon the moon, so as to enable an 
inhabitant of the earth to see distinctly the 
shadows cast by the lunar craters. These cra- 
ters vary in size and form ; some are very large, 
being as much as one hundred and forty miles 
in diameter : many of them appear to have a 
small opening or aperture in the centre, which 
is surrounded by a ridge, or this appearance 
may be merely a peak in the centre of the 
crater. Even during one night a considerable 
change occm-s in the appearance of a crater, in 
consequence of the rise of the sun, as the 
shadow cast by the side of the mountain 
will decrease, fresh peaks become illuminated, 
and various irregular lines of hills appear to 
alter their form. Much of the beauty of con- 
trast produced by the variation of light and 
shade is lost when the sun shines nearly verti- 
cally upon any part of the moon ; thus the full 
moon is not so interesting an object for exami- 








■wo2Mes. 



YmcenvBrods^IiiL 



1. Craters on , liVIplioiiso kc. ' 7. lIa.iiro ly cii s . 

S-SouOi of Mooji . neaj^ Maic :viibiixm.. 8.Aj^ejmme^ 

2. Craters West iS.Posidomas . . 9. lydio 

of jsppenn ines i 6 . Wes tborder of Mare lin bnum 



IX THE HEATEXS. 93 

nation as is the same orb when about one-third 
of the illuminated surface is directed towards 
the earth. 

On Plate 5 are sketches of various portions 
of the moon's surface taken at different periods. 
These sketches have been made with a small 
but very good telescope, and may serve to show 
the great irregularities upon the face of our 
satellite. 

On Plate 4 is a diagram of the moon taken 
when she was partly visible. It will be seen 
from these that the lower and left-hand side of 
the moon are those parts which seem to be 
the most covered with craters. 



94 COMMON SIGHTS 



CHAPTEE V. 

YENUS. 

The celestial object which appears at times 
the next largest to the moon, is the planet 
Venus. The brilliant white light reflected by 
this planet, and the fact of her being a morning 
or evening star only, and never visible during 
the middle of the night, caused considerable 
attention to be directed towards her from the 
earliest ages. 

One of the most important steps towards 
obtaining an interest in the movements and 
condition of the various celestial bodies, is to 
be able to tell whether the object which we 
see is a planet or a star, and also which of the 
planets it is that we may have seen. 

It is very rarely indeed that there can be 
any mistake in connection with the planets, 
and the slioiitest reflection will enable us to 



IN THE HEAVENS. 95 

decide when we see a planet, whether it is 
Venus, or Mars, or any other. 

There are only two planets which appear of 
a large size, and which shine with a bright 
whitish light. These two are Yenus and Ju- 
piter. Mars, wliich sometimes appears as large 
as either of the former, always exhibits a 
bright red appearance, and cannot therefore be 
mistaken for them. In discerning therefore be- 
tween Venus and Jupiter, there might possibly 
be some confusion, but merely at a particular 
period. 

Venus is never very distant from the sun, 
and only rarely remains above the horizon 
more than an hour or two after the sun has set. 
She may rise also two or three hours before the 
sun. Thus she either immediately follows or 
precedes the sun. But Venus is never seen at 
midnight in any but very high latitudes north 
and south ; nor is she eve-r seen of an evening 
in that part of the heavens opposite to where 
the sun has gone down. Thus, if a very bril- 
liant white-looking celestial object is seen near 



96 COMMON SIGHTS 

tlie western horizon in tlie evening shortly 
after sunset, or in the east just before sunrise, 
then this object is most probably Venus. 

If the planet Jupiter be in the same locality 
he will appear smaller and less brilliant, be- 
cause he will then be at a very great distance 
from the earth. Thus, even without any tele- 
scope, the planet Venus ought to be recognized ; 
but with the aid of one, no mistake can occur, 
for reasons which will be stated at a future 
page. The reason why Venus is never seen 
very far from the sun, is, because tliis planet 
moves around him in an orbit which is within 
that which the earth follows. Thus the earth 
never is between Venus and the sun, but Venus 
may be between the earth and the sun. 

In the following diagram S represents the 
position of the sun, W V the orbit of Venus, 
wliilst the largest circle represents the orbit of 
the earth. 

When Venus is at V and the earth at E, 
an observer on the earth would be carried 
round by the daily rotation from to P and 



IX THE HEAYEXS. 



97 



to Q. WTien this observer was at lie would 
be able to see Yenus at V whilst the sun was 
invisible ; then when he had been carried to P, 




the sun would be rising. Thus Venus would 
rise before the sun, and would consequently be 
a morning star. She would also set before the 
sun, and would not therefore be seen in the 
evenins:. 



98 COMMON SIGHTS 

If Venus were at AV, then slie wonld rise after 
the sun, consequently from and P she would 
not be seen, on account of the sunlight; but 
when the observer had been carried round to 
Q, the sun would be invisible, but Yenus would 
be seen as an evening star. 

Venus moves round the sun in the same 
direction as does the earth. She, however, 
moves more quickly, and has a shorter distance 
to travel over to perform her annual journey 
round the sun. If we suppose that Venus is at 
V when the earth is at E, then as they both 
move in the direction shown by the arrows, the 
earth would arrive at about F w^hen Venus was 
at E, and she would dm^ing all this time remain 
a morning star. Thus this planet remains 
visible or invisible for a long period in conse- 
quence of the joint movement of the earth and 
herself. 

Venus is found to revolve around the sun in 
about 224 days 17 hours ; but she only returns 
to the same apparent position as regards the 
sun in 1 year, 3 months, and 29 days. That 



IX THE HEAYEXS. 99 

is, in iiiteryals such as this she becomes an 
evening star or a morning star. The reason 
for this, as pointed out in the preceding dia- 
gram, is her motion combined with that of the 
earth. 

The distance of Yenus from the sun is found 
to be about sixty-eight million miles, the earth 
being about ninety-fiye millions. Thus at 
times Yenus comes within about twenty-flye 
million miles of the earth, a distance much less 
than that which eyer separates us from any 
other planet. Eiiowing the distance of Yenus 
from the earth we can readily obtain an ap- 
proximation to her size, about which, however, 
some slight uncertainty exists. It is generally 
admitted, however, that she is rather smaller 
than our earth, she being about seven thousand 
seven hundi-ed and eighty miles in diameter, 
whilst the earth is rather more than seven 
thousand nine hundred. 

Yenus, which appears like any other of the 
planets or stars when seen with the naked eye. 
presents a singular difference when she is ex- 



100 COMMON SIGHTS 

amined with a telescope. A^Tien at her greatest 
angular distance from the sun, she appears to 
be half lighted, and thus exhibits a semicircle 
of brightness, just as does the moon at times. 
If she be seen in this condition dm-ing the 
evening, she will in a few weeks appear to 
approach the sun, and will seem each night 
larger and more brilliant. If she be examined 
with a telescope when she is brightest, the size 
of the illuminated portion will be about one- 
fom'th of the disc of the planet, but in conse- 
quence of her greater proximity, she aj)pears 
larger than when half illuminated. 

As she approaches the sun, the lighted portion 
becomes less and less, until at last she is lost in 
the sun's rays. Dm^ing a few days she is in- 
visible, and then reappears as a morning star, 
separates herself from the sun, and reaches 
about as far from him on the one side as she 
formerly did upon the other. When at the 
greatest apparent distance from the sun on the 
west side, she will rise about three hom^s before 
him, and if examined with a telesrope will be 



IX THE HEAVENS, 101 

then found half illuminated on the side next to 
the sun. 

The phases of Venus, as these changes in 
appearance are termed, are not the only inte- 
resting facts reyealed when we dkect a tele- 
scope of moderate power towards her. For we 
find that she has an atmosphere like the earth, 
that there are appearances upon her wliich 
lead us to conclude that she has portions 
of her surface covered at times vith snow. 
We can see that she rotates upon an axis, and 
thus has an alternation of day and night, 
and also we know that she has a change of 
season. 

If from the sea-shore we observed two ships, 
each of which possessed a similar hull, masts, 
rigging, and sails, and if from each we observed 
smoke coming out of a chimney, these two ships 
would scarcely be more ahke than are the earth 
and the planet Venus. Each planet has an 
atmosphere, each is spherical, each has a day 
and night, a year, and a change of season. 
Thus when we examine Venus from the earth, 



102 COMMON SIGHTS 

it is almost like looking at our owii planet from 
space. 

When speaking of the moon, we pointed out 
the fact of the whole body of the moon being 
visible when only a slight crescent was illu- 
minated by the sun; and this effect, it is 
believed, can be explained by supposing that 
the earth shines upon the moon. It is singular, 
however, that the same phenomenon has been 
observed upon Venus, the whole of whose 
surface has been distinctly seen when only a 
small portion has been illuminated by the sun. 
It admits of question whether the reflected 
light given by the earth would be sufficient to 
produce this observed effect on a planet as 
distant as Venus. In consequence of the orbit 
of the earth being outside that of Venus, our 
planet would give a much brighter light upon 
Venus than she ever gives to us, because the 
earth when nearest to her would appear ^^fuU," 
whereas she is only seen by us as a partially 
illuminated body. Thus the mliy light of 
Venus might be due to the earth's light re- 



IN THE HEAVENS. 103 

fleeted on to her sm^face. It is not impossible, 
however, that the rotation of a planet upon its 
axis may jDroduce light in some way ; and thus 
Venus and all the other primary planets may 
give out a faint Kght, independent of that 
which they reflect from the sun. When ex- 
amining the system of Jupiter, we will again 
refer to tliis conjectm^e. 

That portion of Venus wliich is nearest to the 
sun, is found to be much more brilliant than 
the central part, where the light and shade 
almost meet. This is a natural consequence 
of the spherical form of the planet, just as 
the midday light on earth is gTeater than that 
in early morning, and the sunlight in equa- 
torial regions more powerful than in high lati- 
tudes. 

There is an additional obscuration of light 
upon Venus, which has led to the conclusion 
that she is surrounded by a highly refractive or 
dense atmosphere ; a condition which it is not 
improbable has been produced by her great 
annual chanR^e of climate. 



104 COMMON SIGHTS 

The surface of Venus is covered with darkish 
spots of a deKcate character, and they occupy 
the greater portion of her diameter. Sometimes 
bright spots are observed upon various parts 
of her surface, or her atmosphere. These, 
however, have enabled astronomers to decide, 
that she rotates upon her axis, in a period 
of about twenty-three hours and tv/enty-one 
minutes.- Thus her day is rather shorter than 
the terrestrial day. 

The method of discovering the time of a 
planet's rotation is to watch for some remark- 
able spot to appear upon the planet, and to 
correctly fix the relative position of this spot ; 
then in some period either gTeater or less than 
twenty-four hours the spot will appear to have 
moved round the planet, and to have regained 
its first position. Some doubt might, however, 
exist, whether the spot had moved round only 
once, or whether two rotations or more had 
occurred during the intervals of observation. 
This question, however, may be settled if we 
observe the change which takes place in the 



IX THE HEAYEXS. 105 

position of the spot during an hour or two^ for 
we can then estimate about the rate of rotation, 
and are not likely to make any very gTeat 
mistake or to confound a double with a single 
rotation. 

In addition to the rate of rotation, another 
interesting fact is ascertained by an examina- 
tion of the spots upon Venus, viz., we can find 
the relative changes which occur in the sun's 
altitude dmino' the Venus vear. This chano'e 
is found to be very great, and is of sufficient 
interest to attract special notice. 

If we examined from space the rotation of 
the earth during the two periods of summer 
and winter, we should find that the rotation 
took place at such an angle in connection with 
the position of the sun, that all localities 
within twenty-thi'ee degrees and a haK of one 
of the poles were durino; the twentv-four hours 
shone upon by the sun. If, however, we ex- 
amine Venus under similar conditions, we find 
that all localities within about seventy-five de- 
gi^ees of one of the poles are shone upon by 



106 COMMON SIGHTS 

the sun during tlie twenty-four lioui^s. The 
course of the spots upon the earth and Yenus 
may be better understood by the following 
figTires. 

Earth. Venus. Venus. Earth. 

^^ " .^^S::^ 3 __. -— _j^ 

^'- ^ :-- - -Sto ^^^^^M- (iUA^J 

^^^^^^ 






Ij 2, 3, show the direction pursued by a 
spot on the earth and on Venus. When, there- 
fore, we remember that the planet revolves 
round the sun, and thus turns towards it in 
summer that pole which was turned away from 
it in winter, we shall see that gTeat variations 
will occur in the two seasons in consequence of 
the variations in altitude of the sun above the 
horizon. To fully understand these changes 
we will suppose ourselves transferred to the 
planet Venus, and to a locality exactly simi- 
larly situated to England upon this earth. 

Here then we stand upon the sm-face of an- 
other world,^ which may or may not present 



IN THE HEAVENS. 107 

very singular variations from oiu' own, — who 
shall say? We commmence our observations 
at that 23eriocl when the sun is over the equator, 
in the spring of the year, a date corresponding 
to the 21st pi March upon earth. Instead of 
that gradual advance from spring to summer 
which terrestrial beings observe, we in Venus 
find that the summer comes with a rush, as it 
were. On earth it takes three months for the 
sun to pass from its spring altitude to its 
summer, and even then it is not nearly over- 
head to people in England. Thirty days after 
the sun crossed the equator of Yenus, it would 
at midday be dh^ectly overhead to a locality 
similarly situated to England, 

Upon earth the only places where the sun is 
seen directly overhead is within tropical re- 
gions, that is, in latitudes not exceeding twenty- 
three and a half degrees. On earth, however, 
in those latitudes, the sun only remains about 
twelve or thhteen hom-s at a time above the 
horizon, and thus the intervals of sunlio-ht and 



108 COMMON SIGHTS 

darkness are equally cliyicled ; the intense heat 
of the day disperses itself in a measure during 
the nighty and heavy dews moisten the ground, 
and thus enable the inhabitants to endure the 
midday heat of the morrow. 

This is not, however, the condition of Venus 
in the regions similarly situated to England. 
There the sun, as we have said, is vertical at 
midday, but it then passes obliquely to the 
western horizon, glides down to the north, just 
touches the northern horizon, and returns again 
to the zenith of our locality. 

Thus in about forty days after the sun has 
crossed the equator it would be vertical at 
midday, and would not set at midnight, and 
twenty-fom^ hours of sunlight would have to be 
endured if England were situated on Venus. 

From this date the sun would not set during 
the twenty-four hours, but would each night 
rise higher above the northern horizon, until 
in about fifty-six days it would daily describe a 
small circle in the heavens, the midday light 



IN THE HEAVEXS. 109 

of the siin being about equal to that of our 
Slimmer sun, and the michiight sim il ar to that 
of spring. Thus for about thiity-two days and 
nights the sun would not set. 

On earth we can see the midnight sun if 
we travel into high latitudes, but we cannot 
see such a sight as a midday vertical sun and 
a midnight sun during twenty-four hours ; nor 
can we do more than imagine the intense heat 
which would be produced by such conditions 
as those which exist in Venus. From the 
period when the sun described its small diurnal 
cncle in the heavens until it again passed the 
zenith at midday, and touched the northern 
horizon at midnight, there would ela]3se about 
thirty-two days. The retreat of the sim would 
be as rapid as its advance. In one hundred 
and thirteen days the autumn position would 
be reached, and the sun would at midday be 
no higher than he is on earth at the same 
period. 

Just as the summer approached rapidly, so 



110 COMMON SIGHTS 

would the milter, and in about twenty-eight 
days from the period when the sun was in the 
position corresponding to the autumn altitude 
in England on earth, he would be lost sight of 
in the same locality in Venus. A long period 
of some fifty days and nights would now elapse, 
dming which the sun would be invisible, and 
those very localities which were so lately ex- 
posed to an ultra-tropical summer would now 
endure an arctic wmter. There is now no 
light save that of the stars, and hence the 
cold would be as intense as was the heat. In 
226 days the sun again returns to the spring 
position, and the yearly changes on Venus 
have been accomplished. 

These are strange conditions to be going on 
in a planet so near our own ; and it is difficult 
to avoid reflecting upon the changes which 
must be produced thereby. Each year an 
arctic winter, and a tropical summer, will 
alternate from her poles to within about 
fi.fteen degrees of latitude from her equator. 



IN THE HEAYEXS. Ill 

It would thus take some time for terrestrial 
beings to become acclimatized in Venus ; but 
who can say whether the creatures which exist 
upon her may not occasionally suffer from these 
very changes ? 

In her equatorial regions there may be 
troops of giant mammoths, which, attracted 
by the scent of the rapidly growing vegetation, 
are travelling northwards, as the sun in its 
northward course vivifies the face of the 
country. Onward they stalk, farther and 
farther, revelling in the shade of trees which 
the sun's heat has produced. During a hundred 
days these herds track far away from the 
equator, and enter the now glowing lands of 
the north. The sun performs its daily circles, 
but is again returning south, and the air begins 
to feel chill, and darkness at midnight warns 
the ancient bulls that it is time to migrate. 

Some members of the herds have strayed 
away however; their fate is sealed, for the 
country which but lately glowed with sun-heat 



112 COMMON SIGHTS 

and was covered with succulent vegetation, is 
now a dark, bleak, snow-covered wilderness ; 
the water is frozen^ the vegetation withered, 
and the mammoth, crunching the dried 
branches, is forced to yield its life, unable to 
procure water, and incapable of sustaining the 
intense cold which penetrates even through its 
wool-covered hide. Many a monster might thus 
perishy and his bones would cumber the soil. 

Another season of heat, however, would 
shortly retm-n, — the snow would be rapidly 
melted, the pent-up streams thawed, and torrents 
of water thus produced would flood the country, 
carrying stones, sand, and icebergs with their 
burdens of boulders into strange regions, whilst 
the mammoth would be borne with the current 
and deposited amidst a mass of debris, near some 
watercourse, from which, centuries afterwards, 
when the planet's condition had changed, some 
geologist might exhume him, and speculate upon 
the cause which had produced such destruction 
amongst his fellows. 



IN THE HEAVENS. 113 

There again is a mass of rock which is an- 
nually exposed to a process similar to that said 
to have been adopted by Hannibal when he 
crossed the Alps. A vertical sun raises this rock 
to a great heat during an uninterrupted period 
of several weeks, then the sun's absence exposes 
it to very great cold ; a change which w^ould 
probably cause the rock to split and separate, 
thus liberating large masses, which would be 
each year subjected to the action of the torrents, 
and which probably at length would become 
frozen into icebergs, and transported as boulders 
to distant plains. 

Owing to the annual alternations of climate in 
Venus, there must be glaciers and moraines, even 
vipon moderate elevations, in all localities down 
to within about twenty degrees of her equator. 
Not only would these glaciers exist upon hills 
where they do not at present upon earth, but 
they would be found to produce effects more 
powerful than any which we can observe ; for 
the effect of .the vertical sun iii summer oyer 
regions covered with snow would be very 

I 



114 COMMON SIGHTS 

powerful. If our polar regions were subjected 
during a couple of months to a nearly vertical 
sun, the ice in those latitudes would be liberated, 
and w^ould be floated by the earth's rotation 
down towards the equator. Thus a whole fleet 
would be sent annually from the poles. In 
Venus the arctic ch'cle reaches to within about 
fifteen degrees of the equator ; and therefore 
nearly all localities, to the north of this, would 
be covered with drift and water-worn materials 
each year. 

Thus, whatever other local circumstances 
may affect Venus, stiU the sudden change from 
a vertical sun to no sun at all, must produce 
these alternations of climate, and probably that 
planet may be now passing through her glacial 
epoch. 

An examination of the mountains in Venus 
leads to the conclusion that they are much 
higher than any at present on earth. It ap- 
pears that they in some instances are as much 
as a hundred and forty-fom^ thousand feet above 
the ground around them. Thus these mountains 



IN THE HEAVENS, 115 

are twenty-seven miles in height, while those upon 
earth do not exceed five miles. It is not impro- 
bable, however, that the great change of climate 
which we have spoken of as occmTing on Venus, 
may, in thousands of years, so rend and crack the 
elevated rocks as to produce greater uniformity 
of surface. At present, however, her mountains 
are enormous. 

It has long been a question whether Yenus 
possesses a satellite. It was stated by some of 
the earlier continental astronomers that they 
had distinctly seen one attending her; and 
some even went so far as to give the period of 
revolution of the supposed satellite. Modern 
observers, however, have not admitted the truth 
of these statements. This is a subject well suited 
to the inquuy of amatem-s ; for a good eye, a 
good telescope, and a little perseverance are 
all the requisites for investigation. As far as 
the matter has gone, the evidence is decidedly 
in favom- of Venus having an attendant ; which 
may, however, be liable to great variations in 
brightness, just as are the satellites of Jupiter. 



116 COMMON SIGHTS 

Not only as regards her proximity and 
phases, but for many other reasons, our nearest 
neighbour Venus is an object of interest, and 
is well worthy of telescopic investigation. 



IN THE HEAVENS. 117 



CHAPTER VI. 

JUPITEE. 

Almost rivalling Venus in brilliancy and 
apparent size, Jupiter is the next object to 
which we shall dii^ect our attention. This 
planet shines with a pale light, and is at all 
times remarkably brilliant, but most so when 
he is in the south at midnight, because then he 
is nearest to the earth. Jupiter is by far the 
largest planet in the system, and exceeds the 
earth in size as much as the eg'R' of an ostrich 
exceeds that of a sparrow; he being nearly 
ninety thousand miles in diameter^ whilst the 
earth is less than eight thousand. His distance 
from the sun is very gTcat, and his year a long 
one ; the first being four hundred and eighty- 
five millions of miles, and the latter nearly 
twelve of om' years. Thus Jupiter can never be 



118 



COMMON SIGHTS 



nearer to the earth than about four hundred 
million miles. 




Jupiter. 



The receptability of ligM of tHs planet must 
be very great, for he appears nearly, if not 
quite, as bright to us as does Venus ; yet the 
one throws his reflected light four hundred 
milUon miles and the other only about sixty 
million, and Jupiter is more than seven times 
as far from the sun as is Venus. 



IX THE HEAVENS. 119 

Jupiter may be seen at any time of niglit, in 
consequence of his orbit, or course, being out- 
side that of the earth. From his large size and 
great brilKancy he is not likely to be mistaken 
for any other planet or star, unless it be the 
Dog-Star, called also Sirius ; but as the position 
of Sii'ius will be pointed out at a future page, 
even this mistake ought not to occur. 

However much we may be accustomed to 
deal with figures, we still fail to realize the 
great distances of the celestial bodies, and 
hence the vastness of the universe, unless we 
are more forcibly reminded of these distances 
by some comparison with terrestrial objects. 
Thus we may better comprehend the distance 
of Jupiter from the earth, when we find that 
if an express train, travelling continually, 
started from the earth towards Jupiter when 
he was at the shortest distance from us, it 
would occupy more than nine hundred years 
to reach him, although it travelled at the rate 
of fiftv miles an hour. 

Jupiter will always be visible during nearly 



120 COMMON SIGHTS 

Dine months in the year, the period when he 
is invisible is when he is behind the sun. When 
first observed as a morning star he is not very 
brilKant, nor does he appear so large as he 
will when he is a midnight star. 

If when Jupiter is first observed as a morn- 
ing star, we notice the stars which appear to 
be close to him, we shall find that each morn- 
ino' he will when he rises be a little more to 
the east of these stars ; that is, he will appear 
to have moved to the left of the stars near him. 
This change in his apparent position will con- 
tinue for several days, after which he will 
gradually slacken the rate of his movement, 
and will then not appear to change his place 
amongst the fixed stars. After remaining 
stationary during two or three days, he will 
then appear to move in the contrary direction, 
that is to the right, and he will continue this 
motion for some months. He vvill then be- 
come stationary, and will again move to the 
left. 

These apparent changes of position, in a 



IN THE HEAVE:NiS. 121 

remarkable celestial body such as Jupiter, 
caused tlie ancients to direct tbeir attention 
particularly to these " wanderers/' as they called 
the planets. The movements of the planets 
ap23eared to them, however, hopelessly intricate ; 
and probably even to modern observers, who 
have never devoted any great attention to 
tlie details of the celestial worlds, the above ex- 
planation may appear to indicate that intricacy 
is one paramount obstacle to thoroughly under- 
standino- the motions of the different celestial 
bodies. 

A little sketch may often do away with the 
apparent confusion of a description ; and such, 
we believe, will be the result in the present 
case if the following diagram be examined. 

The orbit of Jupiter is represented by the 
circle J K L ; that of the earth by the circle 
E F G; the sun is shown at S, and three 
stars are represented at B A C. The earth 
we will suppose to be situated at E, and Jupiter 
at J. Jupiter would now appear from the 
earth close to the star A, w^hich, however, is 



122 



CO^OIOX SIGHTS 



infinitely farther off than is Jupiter, but the 
two would appear close together in the sky. 




In about four months the earth would have 
moved to F, and Jupiter to K, whilst the fixed 
stars ABC would not have altered their positions. 
AATien the earth was at F and Jupiter at K, 
he would appear close to the star C, and there- 
fore he would seem to have moved, as regards 
the stars, to the left. In about three or four 
months from the last period, the earth would 



IN THE HEAVENS. 123 

have readied G-, and Jupiter would be at L. 
Jupiter would now appear to have moved to the 
right of the star C, and to be close to the star B. 

Thus we have &st an apparent movement 
to the left ; then Jupiter is stationary ; then he 
appears to move to the right; then he is 
stationary again; and lastly, he seems to be 
moving to the left, when he is hidden by the 
sun's light. 

All these apparent changes in position of 
this planet are due to the jomt movement in 
the same direction round the sun of the earth 
and the planet. 

AATien Jupiter, or any other planet, moves 
from the right tovrards the left, that is from 
west to east, his motion is said to be " direct^' 
because this is the direction in which the sun 
appears to move amongst the stars during the 
year. When the planet travels in the opposite 
direction, its motion is said to be " retrograder 

Jupiter occupies a period of four thousand 
three hundred and thirty-two days to travel 
round the sun, and thus the Jovian year is 



124 COMMON SIGHTS 

equal to eleven years and three months of 
our time. A Jovian gentleman, therefore, who 
was six years old ought to be thinking of 
retiring into private life, whilst a lad in the 
same planet, aged one year and a half, ought 
to be starting in some profession. 

To circumnavigate the planet Jupiter it 
would be necessary to travel no less than two 
hundred and eighty thousand miles, a distance 
greater than twenty-two voyages to Australia. 

Fontenelle, in his ^ Plurality of Worlds,' de- 
scribes very humorously the supposed con- 
ditions upon Jupiter, The countess says, " ' Pray 
tell me, if the earth be so little in comparison 
of Jupiter, whether his inhabitants do discover 
us ?' ^ Indeed I believe not,' says I ; 'for if we 
appear to him ninety times less than he appears 
to us, judge you if there appears any possibility ; 
yet this we may reasonably conjecture, that 
there are astronomers in Jupiter, who, after 
they have made most curious telescopes, and 
taken the clearest nights for then- observations, 
may have discovered a little planet in the 



IN THE HEAVENS. 125 

heayens, which they never saw before : if they 
publish their discovery, most people Imow not 
what they mean, or laugh at them for fools ; 
nay, the philosophers themselves will not be- 
lieve them, for fear of destroying theii' own 
opinions. Yet some few may be a little cm^ious ; 
they continue their observations, discover the 
little planet again, and are now assured it is 
no vision ; then they conclude it has a motion 
round the sun, and after a thousand observa- 
tions, find that it completes this motion in a 
year ; and at last (thanks to the learned) they 
know in Jupiter that our earth is a world ; 
everybody runs to see it at the end of a telescope, 
though so little that it is scarcely discoverable.' 
" ' It must be pleasant,' says she, ' to see the 
astronomers of both planets levelling their 
tubes at one another, and mutually asking what 
world is that ? What people inhabit it ?' ' iSTot 
so fast either,' replied I ; ' for though they may 
from Jupiter discover our earth, yet they may 
not know us ; that is, they may not in the least 
suspect it is inhabited; and should any one 



126 COMMON SIGHTS 

there chance to have such a fancy, he might be 
sufficiently ridiculed, if not prosecuted for it.' " 

If we were to trace a line in the heavens 
where the sun each year moves amongst the 
fixed stars, we should fijid that Jupiter is never 
very far from this line. He is at times just 
a little above, and at others equally below 
this line ; his greatest variation from it being 
rather more than twice the apparent diameter 
of the sun. 

Upon directing a telescope of even moderate 
powers towards Jupiter, he at once loses the 
star-like appearance which he exhibits when 
seen with the naked eye, and shows a round 
bright disc. Immediately in his neighbour- 
hood there will be seen four, or fewer, little 
bright bodies, which exhibit a constant light, 
differing slightly from that of a star. If these 
bodies be looked at occasionally during an hour 
or so, they will be found to have altered their 
relative positions as regards the planet and 
themselves. 

When a telescope is used with a high magni- 



IN THE HEAYENS. 127 

fying power, Jupiter appears nearly as large 
as does the moon ; and tlie satellites, as the 
small attendant bodies prove to be, also show 
a diameter, and other interesting phenomena. 
AVe will first speak of the planet as he is seen 
by the aid of a powerful telescope, and secondly, 
of the satellites. 

One of the first facts connected with Jupiter, 
and revealed by the telescope, is, that like the 
earth, he turns upon his axis, and thus possesses 
a day and night. An examination of several 
spots upon his surface shows that the rate at 
which this large planet turns round exceeds 
by far that of the earth. The duration of the 
Jovian day and night is about nine hours and 
fifty-six minutes ; and thus these periods of light 
and darkness are nearly " watch and watch 
about," as on board ship. 

In consequence of the shortness of the Jovian 
day and night, there are upwards of ten thousand 
four hundred days in each year, and the various 
bodies on his equator are carried over a space of 
upwards of twenty-eight thousand miles per hour. 



128 commo:n^ sights 

It is supposed that if the earth were to spin 
round with a velocity equal to the above, the 
various objects on the surface would be sent 
flying into space ; such an" assumption, however, 
is only a guess, and it is probable that the 
same force which causes this rapid rotation on 
Jupiter also causes other conditions which keep 
matters in order. 

Some amusing speculations have been made 
as to the supposed height which a cat might 
jump upon the surface of Jupiter, in conse- 
quence of this rapid rotation : of course by the 
aid of a few preliminary but important sup- 
positions, it can be proved that the leap of the 
cat would be enormous. So also might we 
find on earth, by certain theories, how much 
higher v>'e ought to jump at the equator than 
at the northern regions ; and thus the crafty 
foxhunter, by occupying the more equatorial 
portion of the field, might overcome obstacles 
which would effectually "pound*' his less 
scientific friends. As conjectures these theories 
are amusing, but as facts they are not very 



iX THE HEAYEXS. 129 

valuable, for we know not as yet the causes of 
grayity, of a planet's rotation, nor of any of 
those effects which bear upon the question : 
and hence we cannot yentm^e to predict the 
result which might occur by an assumed change 
of conditions ; for we are but upon the sm-faee 
of a law, where we see its effects only, but 
know not the successions of effects which 
intervene between the great First Cause and 
that which our senses enable us to comprehend. 
The various marks upon Jupiter atlbrd a 
means whereby the changes in his seasons can 
be known. These chano'es are verv slight : and 
thus a singTilar difference exists between the 
climatology of this planet and that of Venus. 
The Jovian world has scarcely any change of 
season, provided that the variation in the sun's 
altitude is the only cause of change; for the 
difference between the summer and winter alti- 
tude of the sun is less than seven degrees, 
whereas on om- earth this difference amounts to 
nearly forty-seven degrees. The equatorial 
regions of Jupiter must therefore be much 

K 



130 COMMON SIGHTS 

hotter than regions either to the north or 
south, whilst his polar regions are either 
eternally frozen, or upon the verge of a frost. 
There may be, and probably are, conditions 
upon that planet which fit it for the residence 
of beings possessed of senses perhaps higher 
than those on this world. 

It would appear to follow as natural, that the 
central portion of Jupiter should appear much 
brighter, than either the northern or southern 
regions, for the first locality receives the ver- 
tical, whilst the other receives the oblique rays 
of the sun. This conclusion agrees with obser- 
vation, which indicates a brightness in the 
central portions nearly double that of the ex- 
treme northern and southern regions. 

In addition to the spots which serve to indi- 
cate the rate of rotation, there also exist on 
Jupiter several singular dark and light streaks, 
called " helts^ These belts are all parallel to 
each other, and run across the planet in the 
same direction as his equator ; that is, they all 
lie across him from east to west. 



IX THE HEATEXS. 131 

There have been instances recorded when 
there were no belts seem upon Jupiter, and 
yet at the same time clouds were visible in his 
atmosphere. Thus the belts change their a23- 
pearance, or yanish. They also seem at times 
to be brighter than the surface of Jupiter, or 
darker, according to chcumstances. There is 
usually seen a brig:ht central belt, bordered bv 
two darker lines; but it is singular that these do 
not appear to extend quite to the margin of the 
planet. 

WTiat these belts are is a matter of conjec- 
ture. It has been suggested that they are the 
effects of strong trade winds, or of lone tracks 
of fluid somewhat similar to water : but nothing 
satisfactory is yet kno^Mi, and the belts of 
Jupiter remain subjects for speculation and 
observation. 

Of late years attention has been di^awn to 
several bright spots upon Jupiter. During the 
years 1850 and 1857 some notice was taken of 
this phenomenon, and considerable interest has 
been excited therebv. Like the belts, how- 



132 COMMON SIGHTS 

ever, these spots are mysterious, and they may 
serve to remind us how little we yet know of 
the laws which govern the universe and pro- 
duce changes in the various A^'orlds ; for not only 
are the spots on the sun mysteries, but the 
rapid rotation of Jupiter, his belts and bright 
spots, the ring of Saturn, and the purpose 
for which comets come, and a host of other 
phenomena, remain for future generations to 
explain. We may boast of being able to fore- 
tell for an immense period the time when an 
eclipse will happen, but we cannot predict the 
state of weather for even a week, and scarcely 
for twelve hours : yet as far as the convenience 
and benefit of society is concerned, the latter is 
the more likely to be practically useful. When 
we look back, and consider the advance w^hich 
has been made in science within a few cen- 
turies, we may even hope that the state of 
weather will eventually be predicted, with at 
least some foundation upon truth ; and perhaps, 
when the means of prediction have been dis- 
covered, we shall stand and wonder, lost in 



IX THE HEAVENS. 133 

amazement how such a simple law was so long 
overlooked by our predecessors. 

During the autumn of 1857, when observing 
Jupiter with a telescope of moderate power, 
I noticed a singular appearance both above 
and below his poles. From the extremi- 
ties of the axis there were two streams of 
bright hght, in appearance like the tail of a 
comet, chverging as they receded from the 
planet, and plainly visible to a fhstance of ten 
diameters in both du-ections. The light ap- 
peared to vary in brightness and extent, and 
the phenomenon was very like an aurora. 
I &st supposed that this appearance was due to 
some defect in the object glass, but having ele- 
vated the telescope so as to be well clear of 
the light of Jupiter, I used the slow-motion 
screw to move the axis of the telescope across 
the observed light. Having performed this 
operation several times, and finding exactly 
the same appearance, I concluded that the phe- 
nomenon was connected with the planet Jupiter, 



134 COMMON SIGHTS 

and not mth the telescope. Fortunately two 
friends came the same evening to the observa- 
tory, and upon looking through the telescope at 
Jupiter, they observed the same appearance ; 
although when we directed the instrument to a 
star of the first magnitude, no such effect was 
visible. The night was one of the clearest and 
best suited for observation that I have ever 
seen. 

A few nights after, the atmosphere was 
again suitable for delicate observations, and 
Jupiter was re-examined. Instead of per- 
ceiving the aurora-hke lights from the poles, 
there now a,ppeared a much more feeble, but 
still a similar light on each side of the equator, 
and consequently at right angles to the former. 
These appearances are sufficiently remarkable 
to be recorded. 

It may be a question for consideration 
whether a very brilliant au-rora on earth 
might not be seen, if there were an observer 
with a good telescope upon Mercury or Venus ; 



IN THE HEAYEXS. 



135 



and the phenomenon obseryecl upon Jupiter 
bore a strong resemblance to this terrestrial 
paradox. 

How TO FIXD JUPITEE UNTIL 1872. 

December, March, June and September, 
show the positions of the earth at these periods ; 



1871 



^872 



1S70 



/1861 



pher's Positions until 1872. 



1869^ 




the dates 1861, 1862, etc., show the positions of 
Jupiter at those dates. Remember that the 



136 C03IM0N SIGHTS 

sun is south at noon, and that the earth tin^ns 
round as shown by the small arrows. Jupiter's 
position may then be found at any time and 
season. 

In June 1861 the sun will be south at noon, 
and Jupiter (see 1861, fig.) will be south shortly 
after the sun. Thus Jupiter follows the sun, 
and will be visible for a short period above the 
horizon just where the sun has set. 

Where will Jupiter be seen at 6 o'clock p.m. 
in March 1862 ? 

The sun being south at noon, then at 6 p.m. 
in March the south would be in the direction S, 
therefore Jupiter (see 1862) would be in the 
east. 

WTiere will Jupiter be in September, 1869, 
at midnight ? 

The sun being south at noon, the south t\i11 be 
in the direction 1868 at midnight, and Jupiter 
will be seen to the east of south. 

In April, 1869, Jupiter would be invisible, 
because behind the sun. 



I^' THE HEATEXS. 137 

In December 1870, at 11 p.3I., Jupiter would 
be seen to the south. 

Thus, by remembering that east is to the left 
of south, west to the right, and that the celes- 
tial bodies move fi'om east to west each night, 
we may always Iniow whether Jupiter will 
become yisible during the night, or where he is 
to be seen at any hom\ 

Jupiter is attended by foiu' moons, which are 
from two to three thousand miles in diameter ; 
the satellite next but one to the planet being 
the smallest, and the third satellite being the 
largest. Like the rotation of Jupiter, the revo- 
lution of these moons is very rapid; the &st 
satellite, although at a distance of two hundred 
and sixty thousand miles fi'om Jupiter, yet 
revolves round him in about forty-two and a 
half hours. The most distant satellite revolves 
round Jupiter in less than seventeen days, 
although it is more than a million miles from 
him. 

These satellites move round Jupiter; and 



138 COMMON SIGHTS 

appear from his surface to trace in the heavens 
almost the same course that is passed over by 
the sun dm^ing a Jovian year. Thus during 
each revolution of the satellites they will eclipse 
the sun, and will also be eclipsed themselves. 
The fourth, or most distant satellite, is the only 
one which at times passes round Jupiter without 
eclipsing the sun, or being itself eclipsed by 
him. In consequence of the rapid revolution 
of these moons, and the position of the orbit 
in which they move, the inhabitants of Jupiter 
will witness upwards of eight thousand eclipses 
during their year. 

It is quite possible for the four moons to be 
visible at the same time in the heavens from 
Jupiter during the night. The first satellite 
would a23pear about the same size that our 
moon appears to us : the others would not be 
such prominent objects ; still they ought to 
appear larger than any celestial object which 
we can see except the moon. The rapid and 
variable rate of movement of these moons 



IX THE HEAYEXS. 139 

must aftorcl the Jovian astronomers ample 
opportunities for finding their longitncle ; and 
the eclijDses of the sim and of the satellites 
must enable them to keep then- lunar tables 
in order, supposing that they have not yet 
discovered the cause of a planet's move- 
ments, or that they are independent of observ- 
ations. 

The echpses of Jupiter's satelhtes, their 
shadows passing over his surface, they them- 
selves being hidden, or •'•' occulted " as it is called, 
by him, and theh^ passage across his surface, 
aftord the means of finding the time shown by 
a clock at Greenwich, although an individual 
may be in any part of the world. 

In a publication called the ' Xautical Al- 
manac,'* and at about the 500th page, the date 
and time of the various phenomena are re- 
corded. These calculations are made for two 
years in advance, so that a traveller may take 
this publication with him to any part of the 
world. 

'^ Price 2s. Gd. 



140 COMMON SIGHTS 

The following is the tabular arrangement 
adopted in the work referred to : — 



FEBEUARY. 




d. h. m. s. 


I. Oe. D. 


1 21 23 


I. Ec. R. 


2 53 18-5 


I. Tr. I. 


18 36 


II. Oc. D. 


18 44 


[I. Oc.D. 


19 32 


I. Sh. I. 


19 56 


I. Tr. E. 


20 49 


II. Oc. E. 


21 20 



*^* The abbreviations denote as foUows : — Ec. Eclipse. 
Oc. Occultation. Tr. Transit of SateUite. Sh. Transit of 
Shadow. D. Disappearance. K. Reappearance. I. Ingress. 
E. Egress. 

The year is of course indicated upon the 
back of the publication ; the month is shown as 
above, " February." The I. Oc. D. means that 
the 1st satellite is occulted and disappears 
behind Jupiter. The time of this occurrence 
is indicated by the 1 d. 21 hrs. 23 min. ; that is, 
at 21 hours 23 minutes past the midday of the 



IN THE HEAVENS. 141 

1st of February, Greenwich time, the first 
satellite would disappear. The most conve- 
nient time for observing these phenomena is 
when Jupiter is found in the south at mid- 
night, because then he is nearest to the earth. 
The time of an eclipse or occupation would 
then be about 12 hours after noon, and indi- 
cated thus : Id. 12 h. m. s. ; that is, the 
first day a phenomenon would occur at 12, mid- 
night. 

It is of the greatest use to be able to tell the 
Greenwich time when at different parts of the 
world ; and it is even interesting in out-of-the- 
way country places to be able to set om^ clocks 
by the aid of a satellite, distant from us at 
least four hundred million miles. 

The four moons of Jupiter would appear a 
most singular and interesting sight to a terres- 
trial astronomer, as they rapidly traversed the 
sky of the Jovian world. Our one moon, when 
full, is a glorious object, especially when viewed 
through the transparent medium of a tropical 
atmosphere. But the sight of sights must be 



142 COMMON SIGHTS 

the planet Jupiter seen from his first satellite. 
From this satellite the planet Jupiter could be 
seen to exhibit phases similar to those of our 
moon. Instead, however, of appearing a small 
body, like our satellite, Jupiter would appear a 
huge sphere, measuring in diameter more than 
thirty-eight times the diameter of our moon. 
Such a splendid body must, we should conceiye, 
when illuminated by the sun, cause the re- 
flected light cast upon the satellites to be nearly 
equal to the sunlight. Our telescopes, how- 
ever, do not clearly show that the side of the 
satellites nearest to Jupiter is much brighter 
than the side away from him, although in the 
first case there is the joint light of the sun and 
Jupiter, whilst in the second case there is the 
sunlight only. Thus it is evident that in spite 
of the distance of the sun, its means of light- 
ing the various worlds are such that Jupiter 
and his satellites are as brilliant as any bodies 
in the system ; and hence we are led to the 
conclusion that there are numerous other con- 
ditions affecting the amount of light wliicli a 



m THE HEAYENS. 143 

planet obtains besides merely its mean distance 
from the sun. 

The Jovian satellites are subject to great 
variations in brightness, and in thek apparent 
size. The third satellite is that which is almost 
always the brightest; but from observations 
made in the year 1707, this satellite was found 
to have so much decreased in brilliancy, that its 
light was less prominent than that of the three 
other moons. It has been supposed that there 
are spots upon the satellites, and that these 
spots vary in extent; hence the brightness of 
the different moons would vary inversely as the 
size of the spots. 

There appears to be but little doubt that the 
satellites of Jupiter are surrounded by an atmo- 
sphere. M. Cassini in 1678 remarked that he 
could not perceive the shadow of the first 
satellite as it passed across the surface of 
Jupiter, although the spots upon it were clearly 
visible. Hence he concluded that the satellite 
was surrounded by an atmosphere which pos- 
sessed considerable refractive power, which thus 



144 COMMON SIGHTS 

caused the sun's rays to bend round, and to 
decrease, if not entirely to do away with, the 
satellite's shadow. If this supposition be cor- 
rect, and these satellites do possess an inde- 
pendent atmosphere, it would appear that they 
are in a more advanced condition than our 
moon; and thus the planet Jupiter, with its 
attendants, may be a young solar system, the 
secondary members of which are passing 
through their great geological periods, obedient 
to a prearranged law, which shall fit them to 
support their various phases of vegetable and 
animal life, and at last to receive upon their 
surface the ima2:e of the Creator. 

The colour of the satellites is found to differ, 
although they shine merely by reflected light. 
Sir W. Herschel states that he found that the first 
satellite had a whitish tinge ; that the second 
possessed a bluish white, which varied slightly. 
The third was always white, whilst the fourth 
was of an orange-red colour. Later observers 
consider that the fourth satellite is of a bluish, 
and the thu^d of a yellowish colour, whilst 



IX THE HEATEyS. 145 

that of the first and second inclines towards 
blue. 

A somewhat unphilosophical system has of 
late years crept into that which may be called 
exact science : this is, to assume that all the 
ancient recorded observations which do not 
ao-ree with the modern must have been incor- 

o 

rect. There is not the smallest reason to con- 
clude that there are no changes going on in the 
universe ; in fact, the whole history of the earth, 
geological and astronomical, gives direct evi- 
dence to the contrary. Geology especially 
teaches us that our planet has passed through a 
succession of long epochs, each of wliich dif- 
fered in conditions from its predecessor ; and 
thus that change is one of the laws which has 
been ordained by the great Architect of space, 
and of the worlds rolling grandly therein. 
\'\Tien it is asserted that ancient observatioiis 
must have been incorrect heccaise they differ 
from those of the moderns, we must premise 
that no changes have occurred, or are occur- 
rino', in those bodies which have been ex- 



146 COMMON SIGHTS 

amined : and how can we know this ? We can 
merely guess that there is no change ; but our 
guess may be wrong. If, however, we reject 
recorded facts simply because they disagree 
with that which we at present see around us, 
we are putting aside those sound principles of 
investigation and deduction, which have led to 
some of the most important discoveries of 
modern times. 

The satellites of Jupiter may be under- 
going most important changes, which may 
cause their light to vary in colour and in- 
tensity. In the days of Sir W. Herschel 
they reflected light of one colour, now they 
may reflect another coloured light. It is these 
small changes, extending over long periods, 
which will probably, if fairly examined, enable 
us with our advancing collateral knowledge to 
grasp the key which will unlock some of those 
problems that have hitherto defied solution. But 
to deny facts simply because they may differ 
from that which we now see, is a proceeding 
which, if generally adopted, would enable us to 



IN THE HEAVENS. 147 

demonstrate that EDgland had never been 
without railways or steamers, because we had 
always seen her furnished with both. 

If the disappearances and reappearances of 
Jupiter's satellites be observed, it will be found 
that at certain periods the sateUites will pass 
from the western side to behind Jupiter, and 
will, until they seem to touch him, continue 
bright. Instead of reappearing upon his eastern 
side, and being seen bright and distinct as 
before they disappeared, they will not become 
visible until they are at some distance from 
him. Then at another period the satellites 
would move up towards Jupiter as before; but 
they would not m their approach continue 
bright, but would disappear before they reached 
him. When they thus disappeared, they would 
reappear on the eastern side quite bright. 

These changes are due to the position of the 
shadow of Jupiter and the place of the earth, 
and they may be easily understood by an 
examination of the following diagram : — 

Suppose S the position of the sun, E F G the 



148 



COMMON SIGHTS 



earth's orbit, J K L the orbit of Jupiter ; the 
small circles round Jupiter are the course of 
his satellites. If the earth were at E and 




Jupiter at J, Jupiter's shadow would be thi'own 
in the dh-ection J H. As the satelKte moved 
around him, in the direction shown by the 
arrow, and reached the point A, it would then 
be lost sight of from the earth at E, because it 
would have moved behind Jupiter; the sun, 



IX THE EEATEXS. 149 

ho^veve^, would have shone upon it as it dis- 
appeared, and tlierefore it would have been 
bright as it passed behind Jupiter. This same 
satellite would not reappear until it had cleared 
Jupiter's shadow, and had arrived at B : thus it 
would first become visible at some little distance 
from Jupiter, and upon the left-hand side. 

We find Jupiter at K (fig. 2), and the 
shadow thrown in the direction K X. The 
satellite moving around Jupiter as before would 
now disappear when it entered his shadow at C. 
This satellite would be at a considerable dis- 
tance from Jupiter when it was thus lost sight 
of, as will be evident by noticing how far the 
line E C is from Jupiter, for this line represents 
the line of sight from the earth to the satellite. 
This same satellite would be again seen froiD 
the earth when it reached the point D ; it 
would have been shone upon by the sun before 
it became visible, and therefore it would be 
seen to emerge from Jupiter quite bright. 

Thus in the second instance the satellite dis- 
appears before it reaches Jupiter, and reappears 



150 COMMON SIGHTS 

close to liim. In the first instance it disappears 
close to him, and reappears at some distance 
from him. 

In consequence of the satellites having in 
some instances to pass behind Jupiter, and to 
move also through his shadow, they will be 
invisible during a longer period than when 
Jupiter and his shadow appear as one when 
seen from the earth. When -the shadow is 
behind Jupiter, the sun, earth, and Jupiter 
must be in a straight line, and at this period 
Jupiter passes to the south of all terrestrial 
localities at midnight. At this period his 
nearest satellite is invisible for about two hours 
and fourteen minutes ; but when the same 
satellite is observed, and Jupiter and his shadow 
do not appear as one, then this same satellite 
wiU be invisible for about three hours and a 
half. 

The eclipses of the satellites of Jupiter have 
served to reveal a very interesting law of 
nature — viz., that light requires a certain time 
to travel over space, or through that subtle 



IN THE HEAYEXS. 



151 



medium which exists between the yarioas 
worlds in the uniyerse. That there was a hio-h 
probability that the yelocity of light was not 
infinite was suggested as early as the time of 
Francis Bacon. It was not, however, until a 
much more recent period that the matter was 
definitely settled, although it is like most other 
problems — yery clear and simple when we knovj 
it. 

To show how it is known that light occupies 
some time to trayerse space, we will take a 
simple illustration : — 




Suppose E the earth, and X the position of 
Jupiter and his satelhtes, and let us suppose 
that B is another planet with satellites close to 



152 COMMON SIGHTS 

Jupiter, and at exactly the same distance from 
the earth. Now let the nearest satellite of 
these two planets revolve at exactly the same 
rate, let the eclipses and occultations occur at 
exactly the same instant, and in fact let the 
two bodies A and B be exact counterparts of 
each other. 

AVhen the satellite was eclipsed at A, at that 
same instant would the satellite be eclipsed at 
B, the two phenomena occurring at the same 
time. 

Now let us suppose that the planet B and its 
satellite moved slowly away from the earth, 
and in the direction of D, the actual rate of the 
satellite's movements and the period of its 
eclipses being the same as before. 

If we now found that the eclipses of the two 
satellites at A and D appeared to occm^ simul- 
taneously, it would show that the velocity of 
light was infinite ; if, however, we saw that the 
satellite at A appeared to be eclipsed before 
that at D, it would indicate that light occupied 
some time to pass from D to A. If we knew 



IN THE HEAVENS. 153 

the distance A D, and the difference of time 
between the eclipse at A and at D, we at once 
know the velocity of light. For instance, if 
A D were one million miles, and the difference 
in time of the eclipses one minute, then one 
million miles per minute would be the rate of 
light. The true velocity is much greater than 
this, being nearly twelve million miles a 
minute. 

As an additional example to illustrate the 
fact of the velocity of light, let us suppose that 
when the two satellites were eclipsed at A and 
B, a gun w^as fired from each planet A and B, 
the report of these guns would reach E at the 
same instant. Then the same event occurring 
we should find that as B moved away from E 
towards D the report of the gun fired from D 
would arrive after the report of the gun fired 
from A, and thus the velocity of sound could be 
ascertained. Let us substitute a ray of light 
for the wave of sound, and we have exactly the 
same result. 

The distance of Jupiter from the earth varies 



154 COMMON SIGHTS 

considerably ; lie is nearest when he passes the 
south at midnight, and is farthest when near 
the sun in the heavens ; and thus, by the 
variation in his distance from the earth and the 
number of his eclipses in a given time, a means 
is found to indicate the velocitv of lio-ht. 



PL6. 



MARS. 




"^Sncent Brooks.IiLK. 

Spots on Mars and white patches at 
the poles, p rob ahly snow. 



IN THE HEAVENS. 155 



CHAPTER VII. 



MARS. 



A LARGE briglit-red looking object in the sky, 
which does not scintillate like a star, and which 
is visible in a portion of the heavens different 
from that in which the sun has set, is most 
likely to be Mars. In consecjuence of this 
planet lying farther from the sun than the 
earth, it is visible in all parts of the heavens, 
and is thus unlike Venus in its motion. He 
will appear larger and brighter when due 
south at midnight than at any other time^ 
because then he is much nearer to the earth. 
Mars approaches the earth more closely than 
any other planet except Venus, as he is dis- 
tant about fifty million miles when he is 
nearest to us : thus an express train, travelling 
at an imiform rate of fifty miles an hour, would 



156 COMMON SIGHTS 

pass over the shortest distance which separates 
Mars from the earth in about one hundred and 
twenty years. 

Mars is a very small planet, his diameter 
being rather less than four thousand miles, 
although from his proximity to us he is often a 
very remarkable object in the heavens. Placed 
beside the earth the relative dimensions would 
appear as below : — 



( mars] 




EARTH 



\ 



We have mentioned that Venus always ex- 
hibits phases, like the moon, and is never 
visible when fully illuminated, whilst Jupiter 
invariably appears round and bright. Mars, 
however, can at times be seen when the whole 
surface is not visibly lighted by the sun, and 
then his appearance is like that of the moon 
when within a few days of the "full." The 
phases of Mars are visible to us, because we 



IX THE HEATEXS. 157 

obtain a side view of tlie planet wlien he is 
nearly in the same part of the heavens as is the 
sun ; whereas, owing to the distance of Jupiter, 
we cannot see any part of his surface that is 
not illuminated. As early as the year 1610, 
Galileo perceived that 3Iars was not at times 
perfectly round. 

The year of 31ars, being one terrestrial year 
ten months and two days in length, is nearly 
as long as our own. 

When a telescope of moderate power is 
directed towards 31ars, several spots are ob- 
served upon his surface : many of these are per- 
manent, and Cjuite distinct. They appear in 
groups and of various shapes, the gTeater quan- 
tity being situated in northern regions. UjDon 
the same principle that we were able to tell 
that Jupiter rotated upon an axis, we also 
know that Mars partakes of this almost univer- 
sal movement. Thus the day and night alter- 
nate upon this planet, the period from the 
noon of one day to that of the next being about 
twenty-four hours and thirty-seven minutes. 



158 COMMON SIGHTS 

Thus his day and night do not vary much from 
the length of our own. 

The spots upon his surface also show that the 
annual alternations of climate are not very 
different from those on earth ; the variation 
in altitude between the midsummer and mid- 
winter sun being about fifty-seven degrees, 
whilst on our world it is forty-seven degrees. 
There is not, therefore, the great alternation of 
cold and heat which occurs upon Yenus, nor 
the uniformity of climate which exists upon the 
surface of Jupiter. Amongst the various in- 
teresting facts which the telescope has re- 
vealed, not the least is that of the rotation of 
the planets in our system upon their various 
axes, in such a manner that they all have 
either a slight or great variation of season, and 
thus that summer and winter alternate upon 
the surface of each world. That there is every 
reason to conclude that change of season is 
experienced on Mars may be shown by the 
circumstance that around his poles during 
their winter season appear brilKant white 



IN THE HEAVENS. 159 

spots, Tvhich have fairly been looked upon 
as accumulations of snow. The spot around 
the north pole increases in size as the northern 
winter approaches, and is largest at mid- 
^yinter. When the spring and summer ap- 
proach, the white gradually diminishes, until at 
midsummer it is scarcely visible around the 
north pole. Thus, when each hemisphere is in 
winter, the white spots around the pole become 
apparent ; then when the summer approaches, 
the spot disappears. These white spots appear 
more than double as brilliant as any other 
portion of the surface of Mars ; and as they 
merely extend to about the same distance from 
the poles of Mars that our arctic and antarctic 
snows reach fi'om om^ poles, it is reasonable to 
conclude that the climate of this red planet is 
not very different from that of our own. It 
has been found that during the winter of Mars 
the snow extends to about thirty-five degrees 
from that pole which is in winter, but in the 
summer the snow is not more than six or seven 
degrees from the same pole. This is really 



160 COMMON SIGHTS 

that which we should expect from the alterna- 
tion in altitude of the sun between winter and 
summer ; for in summer he would rise at mid- 
day about five degrees higher than our sun 
rises to us, and in midwinter he would be at a 
less altitude at midday than our sun, by the 
same quantity. Thus the arctic circle would in 
Mars extend to about tw^enty-eight degrees and 
a half, whilst our arctic circle reaches only 
to twenty-three degrees and a half from the 
poles. 

It is indeed a singular fact that we can thus 
gaze upon another world, can observe the 
changes of climate upon his sm-face, and we 
may thus keep a register of his severe and 
mild winters. To even have hinted at such 
unheard-of wonders a thousand years ago would 
have aroused the ridicule of many an em23ty- 
headed critic, as would also the idea of much 
which we now have realized. Who shall ven- 
ture to declare that in future ages a means of 
communication may not be discovered between 
other worlds and our own, perhaps by the aid 



IN THE HEAVENS. 161 

of forces as far beyond the subtlety of our 
present electrical force, as the delicacy of this 
communicating agent is beyond that of the few 
methods of telegraphing, or signalling, known 
to the philosophers of the early ages ! It was 
once supposed impossible to make a signal 
beyond the limits of material terrestrial vision ; 
now, however, it is supposed that where we can 
establish the material conductor there only can 
we telegraph, for it is necessary to lay the wire 
by which to speak. Who knows, however, what 
the future may reveal, and how much yet re- 
mains for unborn generations to glean ! 



M 



162 COMMON SIGHTS 



CHAPTEE VIII. 

SATURN. 

We have now to describe a world which pre- 
sents peculiarities not in accordance with those 
which characterize any other member of the 
solar system, with which we are acquainted. 
Although not a very brilliant object in the 
heavens when examined with the unaided eye, 
still when the telescope is used, Saturn becomes 
a most interesting sight. Nearly spherical in 
form, like the other planets and worlds, Saturn 
is furnished with an appendage, the purpose 
of which is not known. Extending around 
him there is a sort of brilliant hoop, which does 
not touch him in any part, but yet seems to be 
a material substance. In addition to this hoop, 
or " ring " as it is termed, there are at least 
eight moons attendant upon Saturn. His size 



JUPITEPu 

and 

liis Satellites . 



PI. 7. 




SATUR^^ 

and 
Ms E in^ . 



"feiceiit Brooks.litJi 



IN THE HEAVENS. 163 

also is considerable, he being nearly seventy- 
six thousand miles in diameter : thus from his 
size, attendant ring, and numerous moons, he 
becomes a most important member of the solar 
system. Saturn, like Jupiter and Mars, may be 
seen in all parts of the heavens, for the planet 
is much farther from the sim than the earth is, 
which consequently may be between the two 
former bodies : thus Saturn may pass the south 
at midnight. 

In consequence of Saturn appearing some- 
what like a star, although he does not twinkle, 
it may aid the amateur to find him in the 
heavens, if we give a diagram, showing where 
Saturn is to be found during the next thirty 
years. No other knowledge will be required 
to enable the reader to comprehend the sketch, 
than to remember that the earth turns round 
during twenty-four hours, and that at noon 
the sun will be south. 

In the centre of the accompanying diagram 
is the sun ; four small spots round this show 
four positions of the earth during the year. 



164 



COMMON SIGHTS 



These four positions are marked December, 
March, June, and September. At twelve 

How Saturn may be found until a.d. 1882. 



Ncfv^l861 




1870 

Saturn's Positions. 



o'clock (noon) the sun is due south ; therefore, 
in December, at midnight, the south would be 
in the direction opposite to the sun ; con- 
sequently A would be south at midnight. 

In December, 1861, we should find Saturn 
nearly south-east at midnight, because A being 
south, Saturn is seen on the left. 



IX THE HEATEXS. 165 

In March, 1863, Saturn would be south about 
midnight; in June, 1870, also south at mid- 
night. 

As all the celestial bodies move from the 
east towards the south, we have merely to 
remember that they pass from east to south in 
six hours, consequently fr^om south-east to south 
in three hom's. Thus if a body is known to 
pass the south at midnight, it will be found in 
the south-east at nine p.m., the south-west at 
three a.m. Then suppose we wish to know 
where to find Saturn at nine P.3i. in 3Iarch, 
1862. Xine p.3I. would be half way between 
six P.M. and midnight, and therefore our south 
would point in that direction at that hour. 
"We see on the sketch where Saturn would 
be in 1862. Thus, at nine p.m. in 3Iarch, 
1862, he would be a little to the left of south. 
An examination of this diagram will show 
where to find Saturn at all times of nio-ht and 
of the year, for the next thiity years. 

Saturn is much farther from the sun than 
either Jupiter or Mars, and as a consequence 



166 COMMON SIGHTS 

his year is a long one, consisting of twenty- 
nine of our years, five months, and sixteen days. 
A terrestrial mortal, therefore, if a resident 
upon Saturn, and yet subject to terrestrial con- 
ditions, would barely live long enough to see 
three summers ; for if he died at the mature 
age of eighty earthly years, he would still 
merely be three years old, according to the 
years of Saturn. 

In s|)ite of the large size of this singular 
planet, still he rotates with gTcat rapidity, his 
day and night consisting of only ten hours and 
twenty-four minutes. Thus a terrestrial day 
and night are longer than two of Saturn's ; and 
therefore during a given period the sun rises 
and sets to the Saturnites more than twice as 
often as he does to the earth-dwellers. 

The ring of Saturn also spins round, and 
with a velocity almost equal to that of the 
planet, as it rotates in about ten hours and 
forty minutes. 

We have before mentioned that all the 
planets and satellites shine only in conse- 



IN THE HEAVENS. 167 

quence of being lighted by the sun ; it is found, 
also, that this ring of Saturn is visible only 
from the same cause ; for the shadow of the 
ring is distinctly visible upon the body of the 
planet, whereas if the former gave out light 
there would be scarcely any shadow. Also it 
is found that the planet casts a shadow on the 
ring, and thus it is known that the former 
shines at least mainly by reflected light. 

We have spoken of tJie ring of Satm^n, but 
the . appendage referred to really consists of 
several concentric rings, which appear to be 
separated one from the other. The extreme 
diameter of the exterior ring is about one hun- 
dred and seventy-six thousand miles, and it 
extends to upwards of forty-eight thousand 
miles beyond the surface of the planet. The 
breadth of this exterior ring is about ten thou- 
sand five hundred mUes, whilst its thickness 
is not more than two hundred and fifty miles. 
From this earth the ring of Saturn will not 
always appear of the same shape, because, 
owing to the movement of the planet around 



168 COMMON SIGHTS 

the sun, and with an axis inclined from the per- 
pendicular, we sometimes see the ring of an 
elliptical form, or as a straight line. In the dia- 
gram which we have given to show the position 
of Saturn during the next thirty years, we have 
also shown the relative position of the ring as 
it would appear from our earth. It will there 
be seen that in the year 1861 the ring will 
appear like a thin streak of light; whilst in 
the year 1868 it will be in its most open form, 
and therefore best suited for observation. 

Conjectures have of course been made as to 
the formation of the ring of Saturn. One of 
the earher astronomers of modern times * sup- 
posed that a number of satellites were strung 
together, and thus formed a continuous body. 
Another individual believed that Saturn was 
once much larger than he is now, and that the 
ring is a sort of remnant of the planet, and which 
has not shrivelled up like the remainder. Then 
it has been supposed that a comet was captured 
by the gravitating influence of Saturn, and the 
* James Cassini. 



IX THE HEATEXS. 169 

comet's tail has now attached itself to the 
equatorial regions of the planet. In ahnost all 
the conjectures which have been made in con- 
nection with this body, there is one preliminaiy 
proposition which appears to have been assumed 
— viz., that the ring was not always an ap- 
pendage of Satm^n. We now know that the 
ring is not a number of satellites strung toge- 
ther, and we also perceive that it is far more 
solid than the tail of a comet ; and thus two 
at least of the speculations are worthless, 
whilst the other mentioned is untenable fi^om 
an absence of facts upon which to base it. 
Within the last few years it has been shown 
that several changes are occmTing in Satiu'n's 
rings, a new ring having been foimd to separate 
itself from the others. This is a fact tolerably 
well ascertained ; and it is an interesting one, 
inasmuch as it indicates that changes of some 
kind are occmTino- in at least one of the mem- 
bers of this system. 

WTien the siuiace of Saturn is examined 
with high magnitH'ing power, several streaks or 



170 COMMON SIGHTS 

belts are observed, somewliat similar to those 
visible upon Jupiter: these belts do not run 
across the planet parallel to the rings, but 
they incline to and from them to the amount 
of several degrees. 

The polar regions of the planet are found to 
vary considerably in brightness — a fact which 
seems to indicate the presence of an atmo- 
sphere, or of changes of temperature. 

Saturn is attended by at least eight moons, 
or satellites, which revolve around liim at dif- 
ferent distances. The nearest moon to him is 
little more than half the distance from his 
surface that our moon is from us, and it moves 
around him in a period of about twenty-two 
hours thirty-seven minutes. Owing to the dis- 
tance of this body, and the position of his ring, 
the eclipses of the satellites cannot be observed 
with such facility as those of Jupiter's moons ; 
but to be able to perceive the eight moons of 
Saturn is a proof that the telescope with which 
we observe is a good one. 



IN THE HEAYEXS. 171 



CHAPTEE IX. 

UEAXUS AXD XEPTUXE. 

Beyoxd the orbit of Saturn, and at a vast dis- 
tance from tlie sun, there are two worlds which 
far exceed in size our own earth. One of 
these, Uranus, moves round the sun in about 
eighty-foui' of om^ years, and is distant upwards 
of eighteen hmidred million miles from the sun. 
The other, Xeptune, occupies nearly a hundi'ed 
and sixty-five years to move round the sun, 
from which he is distant about two thousand 
eight hundred and seventy million miles. 

From the great distance of these two planets 
they present very few peculiarities to the eye 
of the common observer ; for unless examined 
with telescopes with very high magnifying 
powers, their diameters even will not become 
appreciable. Both these planets are attended 
with satellites, probably with many; eight, 
however, are usually assigned to Uranus, and 



172 COMMON SIGHTS 

one or two to Neptune. We have mentioned 
that it appears to be a rule that the satellites 
attendant upon a planet invariably move round 
their primary in the same direction that the 
primary itself rotates. Thus the satellites of 
the earth, Jupiter, and Saturn move around 
from west to east — that is, from right to left 
if they Avere seen from the northern regions, 
but from left to right if seen from the southern. 
If we observe the satellites of Jupiter from the 
northern hemisphere, we shall find that when 
they are moving from right to left they will pass 
behind the planet, but when moving from left to 
right they will pass across his disc. Thus if N S 
i^ were the north and south poles 

A. (^ C of Jupiter, a satellite would 

^ revolve round him from A to 

B, when it would appear upon Jupiter's disc ; 
it would then move on to C. Thus it would 
move from west to east round Jupiter. 

If now we were to turn the axis N S down 
into a horizontal position, and still keep the 
satellite revolving round the equator of Jupiter, 



IN THE HEAVENS. 173 

we should see the satellite move thus — from A 
to B, C, and D (upper figure), or from our west 
over to our east, or thus — 



/ 



A- 



/ 

from A to B, C, and D (lower figure) ; that 
is, from our east over to west, just as we turned 
the north or south pole towards us — hence 
these moons would move with left or right hand 
rotation, just as the north or south pole of Jupiter 
w^as tm-ned towards us. 

The satellites of Uranus appear in this 
manner, in consequence of the axis of the 
planet being turned down, as it were, hori- 
zontally, so that during forty-two years they 



174 COMMON SIGHTS 

would appear to move from east to west, or 
retrograde, as it is termed ; then for forty-two 
years they would appear to move from west to 
east, or direct. 

Some slight confusion has been allowed to 
exist in connection with the movements of 
these bodies, some Aviiters having gone so far 
as to state that their motion was at variance 
with that of all other satellites. The fact is, 
however, as shown above, a simple change in 
their apparent movements, according as the 
one or the other pole of Uranus is directed 
towards the earth ; and as the same pole remains 
turned towards the earth for forty-two years, 
the fact of a change occurring was overlooked. 
We should not be warranted in asserting that 
the sun moved in opposition to the rules of the 
solar system when we observed him from the 
southern hemisphere, and when consequently 
he moves from right to left each day ; neither 
ought we to state that the moons of Uranus 
move in an irregular manner, simply because 
sometimes they will be seen to move with right- 



IX THE HEAYEXS. 175 

hand rotation, and after many years with left- 
hand, just as the north or south pole is tui^ned to- 
wards the sun and earth. It cannot even be said 
that the position of the axis of Uranus is an un- 
usual one, for we know not what is the most 
general position, no two planets being exactly 
alike. The inhabitants of Uranus might as well 
state that our earth's axis was in an excentric 
position, because the sun was neyer vertical at 
midday bevond twentv-three and a half desTees 
on each side of the equator, whereas to them he 
was sometimes vertical, even in polar regions. 
In fact, it is not philosophical to take our own 
tiny earth as a model of perfection, and to 
assume all other worlds either imperfect or in 
an excentric condition, simply because they are 
sKghtly different in some details. Each, pro- 
bably, is admh-ably suited to its position and 
constitution, and may be where it now is, 
simply because, by a prearranged law, it has 
reached the locality to which its atoms at pre- 
sent bear an affinity, and where it will maintain 
the balance of the universe. 



176 



COMMON SIGHTS 



The diagrams below will show the relative 
positions of Uranus and Neptune during the 
next forty years, the rules for finding them 
being the same as those for finding Saturn and 
Jupiter. The ring next the earth is the orbit 

How Uranus and Neptune may be found until a.d. 1900. 




of Uranus, the exterior that of Neptune. Thus, 
referring to Uranus, we know that during May, 
June, and July, from 1861 to about 1876, he 
would not be visible because behind the sun. 



IX THE HEAYEXS. 177 

During Xovember, December, and January, 
however, of the same years he will pass the 
south at about midnight. About ]\rarch; from 
1883 to 18S6, Uranus will be found to the 
south at midnight, whilst at the commencement 
of June, 1900, he will be south about mid- 
night, and not visible in December or Xovem- 
ber. 

Xeptune will not be visible in February, 
3Iarch, or April, for the next ten or fifteen 
years ; September and October being the two 
best months for examining this remote planet 
for the next twenty years. 

Mercuey. 

At certain intervals of about one hundred and 
twenty days a small brilliant red-coloured body 
-v^ill be observed in close proximity to the sun. 
The body to wliich we refer is the planet Mer- 
cury, which is situated at a mean distance of 
about thirty-six million miles from the sun. 
Mercury, like Yenus, will be seen sometimes as 
a mornino; and at other times as an evenino; star, 

N 



178 COMMON SIGHTS 

but it will never appear so far away from the 
sun as will Venus. Tlius either immediately 
after sunrise, or oefore sunset, this planet must 
be looked for. This little planet, which it is 
supposed measures less than three thousand 
miles in diameter, rushes round the sun in a 
period of about eighty-eight days. Thus the 
year of Mercury is only about one-fourth the 
length of our own, and if we lived to be sixty 
years old on our earth, we should be about two 
hundred and sixty years of age, counting by 
the years of Mercury. 

It is found that, like all the other planets 
in the system. Mercury rotates upon an axis, 
and occupies about twenty-four hours and five 
minutes in rotating. It is assumed that Mer- 
cury rotates in such a manner that the sun 
will be vertical each year at midday at all 
localities, except those within twenty degrees 
of the polar regions. Thus, in consequence of 
the quick return of the seasons, and the ex- 
tension of the tropical regions, there would be 
but little time for ice to form upon any part of 



IX THE HEAVENS. 179 

Mercury, as the sun would be absent merely a 
few days even from the extreme northern re- 
gions; thus a very uniform climate ought to 
prevail in that planet, which, with the quick 
return of the seasons, would probably be very 
suitable to the rapid growth of vegetation, espe- 
cially so of that type of vegetable found so 
abundantly in our coal-fields. If then ilercury 
possess a soil and an atmosphere at all analo- 
gous to those of our earth, we might suppose 
that the little planet was now engaged in 
coaling. 

It has been supposed by some observers that 
there are very enormous mountains upon the 
surface of Mercury of a height sufficient to alter 
the shape of the crescent which this j^l^^et 
sometimes shows. Like many other delicate 
observations connected with science, some ob- 
servers assert, whilst others as vigorously deny, 
that these excrescences exist. 

Mercury is seen occasionally to pass across 
the disc of the sun, when it appears a romid 
opaque body, attended by a sort of atmosphere. 



180 



COMMON SIGHTS 



The passage of a planet across the sun is called 

" a transit " across the sun's disc. During the 

next forty years six transits will occur ; viz. 

in— 

1868 . . . Nov. 4. 



1878 
1881 
1891 
1894 
1901 



May 6. 
Nov. 7. 
May 9. 
Nov. 10. 
Nov. 4. 



The planet will occupy about from four to 
six hours in passing across the sun's disc, and 
therefore can easily be distinguished from a 
spot in consequence of the rapidity of its 
motion — a spot appearing to scarcely change 
its position during a whole day. 



CONSTELLATIOKS. 
d ai e f 



?] 8 



fe/ 



IiQ.2. 




a^a . Betelgeux . e .e . ilitf el i^t^. 2. 

l3."b Oi-ioTislDelt. f -f . Tjeflatrdx . Cassiopeia. 

Q. c. Siciiis . Gr.G. ^Mdebaran . Tig. 3 . 

d. d . Saipli . li."h n ei ajd.e3 ^^orth ern Cro^vn . 

ai . The Pointers . 



'/mcerd 2rooT<s hxh 



leg. 4. 

l.l.Tega or alYTse . 
1.2. The Pole Star. 
13. CapeHa 
4.4 . The Great Bear. 



IN THE HEAYENS, 181 



CHAPTEE X. 

THE FIXED STAES, 

To tlie mere casual observer the stars appear 
to be scattered promiscuously in the heavens, 
and to have no special characteristics which 
can distinguish them from each other. A very 
little attention will, however, show that they 
differ in apparent size and brilliancy, that their 
colours vary, and that they are formed into 
groups or patterns which can, when once known, 
bo easily recognized. 

We have mentioned that some of the so-called 
stars are really planets similar to our earth, which 
would probably look like a small star if seen from 
one of them. These planets wander amongst 
the fixed stars, but around a particular course : 
and are therefore to be found at various periods 
near to various gToups of stars. The fixed 



182 COMMON SIGHTS 

stars, as the name implies, never move, or if 
they do, it is merely by the aid of delicate 
instruments and long examination that these 
movements become manifest Hence a group 
of stars can always be recognized because the 
various members do not alter their relative 
positions. 

If the stars be attentively observed for a 
year, it will be found that during summer very 
different constellations will be seen in various 
parts of the heavens to those which are visible 
in the same localities in winter. Some bril- 
liant constellations, also, which we may observe 
dmdng one season are invisible during another ; 
other constellations likewise are always to be 
seen, but are found in different parts of the 
sky, according to the time of the year. 

From the very earliest ages names have been 
given to the principal stars, and also to the 
constellations which are the most prominent in 
the heavens. Thus individuals are enabled to 
speak intelligibly in connection with the sky, 
just as we can with reference to various parts 



IN THE HEAVENS. 183 

of the earth ; for if there were no such names 
as Africa, xlmerica, &c., the world would to us 
be a confused and indefinite accumulation of 
land and water, just as would the heavens if 
the stars could not be known by name. 

If an individual acquainted with the names 
and positions of the yarious stars were to tell 
another Avho was ignorant of them that a comet 
or a meteor had been seen moving from 
Sirius towards Capella, the information would 
be about as interesting and instructive as 
though we told a Bushman that there was free 
trade with France. So far beyond the range of 
his knowledge would such an intimation be, 
that he would probably not trouble his mind 
about the matter. When, however, we know 
the direction or position thus pointed out, and 
also picture to ourselves the probable course 
of the comet, resulting from its movement in 
the direction indicated, and compare this course 
with that of others of which we have read, 
we begin to take an interest in the subject, 
simply because we understand something about 



184 COMMON SIGHTS 

it. For it really appears as though individuals 
were not only indifferent to, but even often 
disliked some subject, simply because they were 
unacquainted even with its mere outline. 

We will first endeavour to explain why it is 
that there are some stars which can always be 
seen in these latitudes ; after which some of the 
principal constellatioi^s will be shown, and also 
their positions at various periods during the 
year. 

A moment's reflection wdll show^ us that our 
view is bounded by the horizon; we cannot, 
therefore, see that w^hich is below the horizon ; 
all, however, that is above may be seen. Then 
let us remember that our earth turns round 
during about twenty-four hours, and we can 
understand the following sketch. 

Suppose the position of any person upon 
the earth, say, for example, in England, then 
the line HOE would represent the horizon 
of this person, and all that w^as above this 
horizon might be seen ; therefore various bodies 
that were situated as T E S A P and X, would 



IN THE HEAVENS. 185 

all be visible from 0. P would be nearly over- 
head, A near the horizon, and lo\Yer down 
than T. 

P TRSA 



-^^ 



X 



•■•Jiiii/ 



In twelve hours' time, the same person would 
be carried by the rotation of the earth round 
to Q, when his horizon would be represented 
by the line P Q IT, From the position Q^ 
E would seem high above the horizon, and A 
much higher than T. P, which was nearly 
overhead when the person was at O, would now 
be just on the horizon, and X which was seen 
from 0, vfould be invisible from Q. 

Thus T E S A ^vould be seen from both 
and Q. The principal difference being, that 
at 0, T was above A, but from Q, A was above 
T. This chano-e would arise merelv from the 



186 COMMON SIGHTS 

fact, that the head of the observer pointed to a 
different direction at from that in which it 
pointed at Q. 

If T E S A are called stars, they would also 
be always visible from the positions and Q, 
bnt X would be a star only visible from 0. 

The stars can only be seen during the night ; 
and in consequence of the earth moving around 
the sun, night Vvould occur on the side or Q 
according to the time of year. \Mien the 
night occmTed on the side 0, then the stars 
T K S A and X would be seen, T being above 
A. When the night happened on the side Q, 
X would not be visible, but T E S A would be 
seen, A being above T. 

Hence there are some stars which are always 
visible during the night from certain localities, 
these stars beins: sometimes nearlv overhead or 
close to the horizon, according to their position 
in the heavens and the time of year. 

Amono' the stars which can alwavs be seen 
from England, the following are the principal. 
The constellation of the Great Bear, also the 



IX THE HEAYEXS. 187 

Pole-st^ir and the Little Bear. The constellatiou 
Cassiopeia, the bright star Capella, called also 
Alpha Aiirigae, the bright star Alpha Lvr^. 
called also Tega. can just be seen on the horizon 
from the south of England when it is lowest, and 
to the north of us. At other times it will be found 
high up, and to the south. Alpha Cygni is 
another bright star always visible from England. 

To enable any person to find the position of the 
various principal stars at any time of the year, 
the following sketch is given : the method to be 
adopted is similar to that for finding Saturn, 
Uranus, &c. Thus we have merely to re- 
member that the sun is to out' south at midday, 
to our north at midnight, and that the earth 
turns round in about twenty-foui^ hours. Allien 
the sun is between the earth and a star, the 
latter is of course invisible, owing to the sun- 
light. By remembering these simple facts, the 
following sketch becomes intelligible. 

The sun is shown in the centre of the dia- 
gram, the earth in four positions according to 
the time of vear. 



188 



COMMON SIGHTS 



For illustration let us see which stars are to 
our south at midnight in December. 



Capella. ^ 




Cassiopeia. 
o. Andromeda. 



Alpha CygnL 



At noon, the sun is to oui^ south, consequently 
twelve hours after noon, that is, at midnight, 
our south will be in the opposite direction. 
Thus Orion^ Eigel, Betelgeux, &c. would be in 
the southern heavens at midnight in December. 
At about 9 P.M. at the same season, a Persei 
and Aldebaran would be nearly south. Stars 
in the direction of Ve2:a could not be seen 



IN THE HEAYEXS. 189 

because of the sun, unless tliey were near tlie 
northern pole of the heavens. 

In Septemljer Alpha Cygni would be south 
about 9 p. M,, Cassiopeia and Andromeda 
about midnight. 

In June, we should not be able to see Sirius 
or Orion in consequence of the sun, whilst 
Capella would be in the north, and visible, 
because it is one of those stars always seen from 
England. Vega would be south at midnight 
at this period, and Altair at about one o'clock 
in the morning. Thus, by remembering in 
which direction the earth tmms round, we can 
always find by this diagram the position of the 
principal groups of stars. 

In March, at noon the sun is south ; at 6 p.3i. 
Orion, Sirius, and the stars near them ; at 9 p.:m. 
EegTdus ; at about midnight Spica ; at about 
3 A.:\r. Arcturus and the Xorthern crown; 
about 6 a.:j:. Yega and Altair. Ako at mid- 
night Sirius will be in the west, and setting, 
Yega in the east, and rising, A sketch of some 
of the principal groups of stars is shown in 



190 COMMON SIGHTS 

Plate 8, so that they may be recognized by 
their forms. 

In addition to the diagram which we have 
given, the position of the various stars may be 
ascertained by the aid of the constellation of 
the Great Bear and one or two other stars. 
The Great Bear is snch a remarkable constel- 
lation that it can easily be found at any time ; 
and hence the Pole-star can be found by the 
aid of the pointers. Then if a line be drawn 
from the Pole-star at right angles to a line 
from the pointers to the Pole-star, then this 
line will pass close to a bright star called 
Capella. 

A line from Capella through the Pole-star 
will, if produced, pass through a bright star 
called Vega or Alpha Lyrse ; thus Capella, 
Vega, and the Pole-star are in nearly the same 
straight line. 

If a line be drawn from the Pole-star through 
the last star in the Great Bear, this line pro- 
duced will pass through Arcturus, a bright 
reddish star, famous to all observers as the star 



IN THE HEAVENS. 191 

near which the brilliant comet of 1858 was 
seen when in its splendour. 

The belt of Orion is another constellation 
easily recognized, hence Sirius becomes known 
(see Plate 8), also Betelgeux and Eigel. Then 
on the opposite side of the belt to that on which 
Sirius is found, and nearly in the same straight 
line, we find a star named Aldebaran. 

Smus, Betelgeux, and a bright star named 
ProcYon, will form an almost equilateral triangle. 

At about one-thuxl of the distance from Arc- 
turus to Vega we find a semicircular group of 
small stars, one of the gTOup being large. This 
large star is named Alphacca, the group being 
the Northern Crowm. 

About midway between the Pole-star and the 
tail-star of the Great Bear, and nearly in the 
direction of a line joining these two, is the 
brightest star of the Little Bear. 

A few minutes' attention directed to the 
heavens any evening will soon enable an 
individual to know some of the principal stars, 
and to find them, if visible, at any time of tlie 



192 COMMON SIGHTS 

year. The principal groups of stars, such as 
the Great Bear, Orion, Capella, Cassiopeia, or 
the Northern Crown can be recognized by theu^ 
form, some of the large solitary stars by theu^ 
position relatively with the Great Bear and the 
Pole-star. 

There is a vast field for speculation and ad- 
miration in the illuminated page spread before 
us during each clear night in the year. When 
we realize the fact that each twinkling star is a 
sun, the centre probably of a system of re- 
volving worlds, each of which may be similar 
to that on which we dwell, we become bewil- 
dered amidst so much grandeur, and may well 
stand insjDired with veneration and awe if 
we reflect upon our own insignificance com- 
pared with the extent of creation. "Wlien we 
behold these millions of suns glittering in the 
midnight heavens, v/e natm^ally ask, for what 
are they intended? It has been said that* they 
are to give light on earth, and this is their most 
obvious use; but is it their only purpose? 
Have all these gigantic bodies, each of which is 



IX THE HEAVENS. 193 

ten tliousancl times the size of our pigmy world 
been created solely for the purpose of casting 
at rare intervals a dim Kght upon us. Such a 
conclusion would partake somewhat of the self- 
sufficiency of man, but would scarcely show 
that we realized the perfect system which has 
been adopted in creation, and the endless variety 
and originality which observation teaches us 
really exists. 

As far as we can judge from facts, it is sup- 
posed that the sun is a solitary member of om* 
system, and that although attended by many 
planets or satellites, he is still without a com- 
panion. We cannot, however, say whether if our 
sun were seen from the Pole-star he would ap- 
pear alone» It is probable that he would ; and 
thus he presents a variation from other stars in 
the universe, some of which possess companions, 
which give out light and revolve round each 
other. Thus two suns belonging to one system 
would appear to indicate a higher or more 
advanced state, and at least to remind us that 
in creation there is an endless variety, both as 

o 



194 COMMON SIGHTS 

regards suns, systems, and worlds, or the most 
minute insects that creep around us. 

Like most novelties, the early announce- 
ment of the fact that several of the stars were 
double, excited ignorant or bigoted critics, who 
compared this supposed condition of the stars to 
the pairs of soles on a fishmonger's stall. Now 
the most accurate observations have shown that 
these stars move round each other, and thus 
from year to year they alter their relative 
position ; hence the name of fixed star is a mis- 
nomer. 

The tliird star from the tail of the Great 
Bear is a double star ; the two stars appearing 
to move round, or the one to revolve round the 
other, in a period of about fifty-eight years. 
Castor, one of the twins, consists of two stars ; 
a period of about two hundred and fifty years 
being assigned to the revolution of one of these. 
Eigel, the Pole-star, e Bootis, y Virginis, a 
Hercules, and many other remarkable stars, are 
double ; in fact, nearly six thousand double stars 
are alreadv known. 



DOTIBLE STARS (Telescopic) 



Ti.d. 




1 /3 CjoTd .3a Geminoruin . b/x Saoittaiii 

2 S Bootis . 4 '■n Cassiopeia. 6 Polai^is . 



7. 51 Iibrce. 



IN THE HEAVENS. 195 

Arcturus is a star which the reader will now 
be able to find. About ten degrees to the north- 
east of Arcturus, or, more definitely speaking, 
about ten degrees up a line drawn from Arc- 
turus towards Vega, we find a star called 
Miraeh, which is double, the contrast of colour 
between the two stars being yery beautiful. 
In addition to double, there are some groups 
of triple and quadruple stars ; the star ap- 
pearing single when seen with the naked eye, 
but triple or quadruple when examined with a 
large telescope. 

By examining the records of ancient astro- 
nomers it has been found that there are varia- 
tions in the brightness of the stars ; some appear 
to be getting dim, whilst others are more 
brilliant than formerly. Some stars have dis- 
appeared entu^ely, as vv^as the case with the 
seventh star of the Pleiades, which it was said 
vanished when Troy was taken. In modern 
times it is found that several stars vary in 
brightness dming certain periods, some occu- 
pying from five to ten days to pass through 



196 COMMON SIGHTS 

their changes, whilst others occupy three or 
four hundred days in returning to their same 
condition. In some instances a star of large 
size has appeared merely for a short time, and 
has then suddenly been lost sight of. 

The principal object to be observed in con- 
nection with the stars, if provided with a tele- 
scope, is the relative position of the double 
stars, and the beautiful diversity of colour 
existing between them. A^Tien the two stars 
become visible in the telescope, it can then be 
seen that they are usually of different colours. 
Some of these contrasts are very lovely : a rosy 
tinge is possessed by one star, its companion 
perhaps a beautiful green ; this is the case with 
a star called 24 Com^ Berenicis. 

The prevaiKng colour of the attendant stars 
is blue or greenish blue. Sometimes they are 
of the same colour as the principal star, but 
this is not usual. 

It is found that certain stars which formerly 
shone with a white or red light, now appear of 
a different colour, and thus there appears to be 



IN THE HEAVENS. 197 

a change of some kind occuiTing in every 
portion of the universe. 

If we examine the earth beneath our feet, we 
find tha.t from the very earliest ages to the 
present time there has been one continued 
change, or onward movement. We may per- 
ceive cropping out in various localities an ac- 
cumulation of hard rocks which formed the 
surface soil in ages long since past : these rocks 
were not capable of affording nourishment to 
plants or trees until they had been submitted 
to certain actions during long periods of time. 

Again, we find that m a subsequent epoch 
plants of various kinds flourished abundantly, 
whilst the earth was still untenanted by a 
numerous class of the animal creation : then 
we recognize a period when animals of vast 
size roamed over our now fair earth, and reigned 
monarchs of the plain, forest, and river ; man 
being still an unknown creature in this planet. 
History teaches us that there was afterwards a 
time when vast hordes of men peopled the 
world, whose minds were comparatively con- 



198 COMMON SIGHTS 

tract ed, and whose aims were limited. If a 
modern savant with his knowledge of tele- 
scopes, steam, electricity, photography, and 
other scientific facts, had existed some seven or 
eight hundred years ago, he would probably 
have been treated as a deity by those who 
were then capable of perceiving the utiKty of 
the subjects with which he was acquainted. 
Thus we find amongst men that progeess has 
been one of the most prominent characteristics. 
Hence from the period of hard unfertile rock 
to that of the present day, there has been one 
onward movement ; and even now we are livmg 
in an epoch which daily presents some change 
by which the crude or erroneous opinions of the 
past become trimmed so as to more nearly ap- 
proach truth, and hence to be more in harmony 
with that Divine wisdom which has created 
all the vast celestial machinery as well as the 
minds by which his works can be compre- 
hended. When we find that there are stars 
which disappeared, changed theu^ colour, ap- 
peared or are variable, we are induced to reflect 



IN THE HEAVENS. 199 

upon the probable cause or purpose of these 
changes, and to form conjectures as to the 
various appearances which our own earth might 
have presented at different times. It is at 
least probable that vfhen a star changes its 
apparent colour there is some change of con- 
dition in that star. Perhaps its atmosphere 
may have become affected by the approach of 
some other celestial body; the electrical or 
magnetic condition of the star may have 
varied, or the body may be passing through 
various epochs and in rapid succession, much in 
the same manner that om^ own planet passed 
through changes which occupied ages of time 
before they were completed. To know that 
creation is not stereotyped in one form is a 
most interesting fact ; and we become aware of 
this whether we observe the distant suns and 
worlds, or examine the earth beneath our feet. 



200 common sights 

Nebulae. 

An attentive examination of the sky during 
a clear night will enable an individual, even 
with the unaided eye, to perceive several 
whitish-looking foggy patches of light, which 
appear somewhat like the mist which at times 
surrounds a bright star. If a telescope of even 
the smallest power be turned towards these 
patches, it will be found that they consist 
merely of an accumulation of small stars 
grouped very closely together. 

When the telescope is dnected to various 
parts of the heavens, there will be seen many 
of these misty patches, which then appear with 
the aid of the telescope very similar to the 
groups of small stars if examined with the 
unaided eye. These groups or patches of misty 
matter are called Nebulse. 

With the aid of the most powerful telescopes 
some of the so-called Nebulae have been 
resolved as it is termed ; that is, they have been 
found to consist merely of groups of stars in 
close proximity to each other. There are still, 



:pi.iO. 



:NrEBrx^ . 




I. In Hercules. 3. In Cassiopeia. o.DumLBell m Mupeada. 
2. ,, Aitinous. 4<. ,, Andromeda. 6. In Lyra. 



IX THE HEAYEXS. 201 

however, several nebulae which no telescopes 
have resolved, and which appear misty even 
when examined with high magnifying powers. 

An observer who may be provided with any 
small telescope will find that he is able to 
resolve some of these patches of light. Alde- 
baran is a star easily found from the descrip- 
tion already given; close to Aldebaran there 
is a group of stars which to the unaided eye 
presents this misty light appearance. There are 
also two patches close to Cassiopeia. 



202 COMMON SIGHTS 



CHAPTEK XI. 

COMETS. 

The most mysterious bodies in the heavens are 
certainly comets. The planets we can readily 
imagine to be, and there appears every probabi- 
lity that they are, the residence of created beings 
of some kind. The sun and the fixed stars ap- 
pear to be the centres of systems to which they 
contribute light and heat. When, however, we 
examine the form and condition of these sin- 
gular wandering bodies which are called comets, 
it is difficult to conceive that they are as yet 
fitted for the residence of any material beings ; 
and it would be no less in opposition with the 
analogy of nature, to assert that they have not 
their use in the economy of the universe. 

In ancient times, it was the custom to state 
and believe, that comets produced diseases and 
losses to princes, as well as to peasants, and they 



Pl.ll. 



COMETS 




1 . Encke's . 

2. Comet of 18 



IX THE HEAVENS. 203 

were thus considered messengers of evil. In 
more modern times these visitors were sup- 
posed to be the vehicles in which the spirits of 
the departed were conveyed to some special 
locality assumed to be that of Paradise. 

Some of the ancient philosophers behaved 
comets to be a sort of meteor which existed in 
the atmosphere of the earth ; whilst others ven- 
tured very daring and, for theu^ time^ unor- 
thodox opinions, and asserted that comets were 
probably nearly as high up as the moon. 

Comets may be divided into two classes, viz., 
those whose course is known and whose reap- 
pearance can therefore be foretold, and those 
whose course is unknown, and whose visits are 
therefore imcertain. 

There are some comets whose course is 
known, and whose return to any point in the 
heavens can be predicted ; but these are insig- 
nificant in appearance when compared to some 
of those brilliant visitors, which gleam for a 
period in the heavens, and then dash away into 
endless space. 



204 C03I3ION SIGHTS 

Comets first become visible to us in a variety 
of ways. The mere searcher of the heavens, 
who night after night directs his telescope to 
various parts of the sky, may at length perceive 
a small speck of light which differs slightly in 
appearance from a star. An examination of 
this body dm^ing a few evenings, may show that 
its position changes very rapidly, and that it is 
moving amongst the various fixed stars. The 
first fact resulting from this discovery would be, 
that the speck of light was either a planet or a 
comet, and a very few evenings would enable 
an observer to decide which of these bodies he 
had discovered. If the comet were approaching 
the sun, it would probably become more and 
more distinct each night, and would soon 
become visible to the unaided eye. When thus 
distinct it usually appears like a small star, 
with a slight ray of light shooting out from the 
bright portion. The mere casual observer 
might not at first perceive any difference be- 
tween this comet and a star ; but a little atten- 
tion would soon shovv^ the difference between 



IX THE HEAYEXS. 205 

the two. If the comet were a large one, and 
passed near the earth, it would become not only 
a remarkable, but a splendid object in the 
heavens. There can then be distinctly seen a 
bright head, or nucleus, as it is termed, and 
from this there are diverging rays of light or 
vapour which extend to a considerable distance 
behind the head of the comet. This brilliant 
body moves on with great rapidity, and is at 
length lost sight of in consequence of its 
approach to the sun. The above description of 
the changes which occur with a comet holds true 
when a comet is seen as it approaches the 
sun. 

With the aid of a diagram we will now show 
the usual course of a comet, and also endeavour 
to explain why they are sometimes seen only 
as they are travelhng away from the sun, and 
why some also suddenly appear, and. of a very 
large size. 

The earth travels round the sun, and at a 
nearly uniform distance, this being the usual 
course of a planet. A comet passes round the 



206 COMMON SIGHTS 

sun, but not completely round it, then travels 
far away beyond the range of our sight, we 
know not where. The respective courses of a 
planet and comet may be understood from the 
following diagram : 



As / Np 

i ^(® i 
e 

The circle A B C D represents the earth's orbit 
round S the sun \ x y z represents a portion 
of a comet's orbit, which may extend to one 
hundred times the distance from the sun that 
the earth's does. If the earth were at A when 
the comet was at x^ the comet would scarcely 
be seen, as it would be so close to the sun that 
it would set immediately after it, and thus on 
account of the light would not be visible. If 
then the comet moved from x \^o y and z^ it 
would reach the point y perhaps when the earth 
was at B, and would thus be invisible in con- 
sequence of the sunlight. Then as the comet 



IX THE HEAYEXS. 207 

moved to z, the earth would have travelled to C, 
and the comet would now be visible for a short 
time just before sunrise. It would be travelling 
from the sun. and at a great distance, therefore 
not a very noticeable object in the heavens. 

If, however, the earth had happened to be 
at the point D in its orbit when the same 
comet was at x, then it would have been dis- 
tinctly visible, and would have been in the 
south about midnight. AThen the earth 
moved on towards A, the comet would have 
passed round towards y, and would thus have 
disappeared. 

Viliether we see a comet distinctly and for a 
long period, as it approaches or moves from 
the Sim, depends therefore entKely upon the 
relative positions of the earth, the sim, and the 
comet. 

Any person, however, although not scientific, 
or acquainted Y^ith mathematics or astronomy, 
can draw a circle, can place the sun in the 
centre of this circle, and can make a mark to 
indicate the position of the earth ; then if it be 



208 C03IM0X SIGHTS 

announced that a comet is visible in any part 
of the heavens at a certain hour, and is moving 
to^Yard, or away from the sun, he can sketch 
the most probable com^se of the comet^ and can 
then see where it is likely to move to. For 
example, suppose a comet were obseiTed in the 
month of September, and was visible at mid- 
night in the south-east — we can draw a circle 



V'C 




jST 



D E, which represents the earth's orbit, S being 
the sun, E the position of the earth in Sep- 
tember, which moves round towards D. At 
midnight in September the south would be in 



IN THE HEAYEXS. 209 

the opposite direction to that of the sun ; there- 
fore the south-east at midnight would be in the 
direction EC. A very few observations would 
show whether the comet was moving towards 
or away from the sim, for if it increased in 
apparent size or brightness, we should know at 
once that it was approaching the sun. This 
comet if approaching the sun would move 
either as shown by the curved line C 31 or 
by the line C T P. Whichever course it fol- 
lowed, it would come very near to the earth, 
and would therefore be a much more remark- 
able object in the heavens than when first 
observed. If the comet moved in the course 
indicated by C T P, we should probably also 
see it upon its return from the sun, for the 
earth would have moyed round towards D, 
whilst the comet had travelled from C to T 
and round towards P. K the comet pur- 
sued the course shown by the line C M, 
we should see it clearly only when it was 
moving towards the sun, for as it moved awav 
it would be between S and M, and therefore 

p 



210 COMMON SIGHTS 

behind the sun, because the earth woukl be 
near the point D. 

If in September a comet were observed at 
midnight in the south-west, this comet would be 
in the direction shown by X. Then as the earth 
moved on from E towards D, and the comet 
from X towards S, it would soon be lost to 
view in consequence of its approach to the 
sun. 

Sonietimes a comet will approach the sun 
Irom what we should call a high point in the 
heavens : when this is the case it may be 
clearly visible in the north at midnight, the 
sun being then in the north, but belov/, whilst 
the comet is above, the horizon. Some very 
fine comets may be seen in this position, the 
last brilliant comet that visited us having been 
during a considerable time in the north about 
midnight, whilst retreating from the sun. xlny 
novice can, however, roughly calculate whether 
a comet is likely to be a very remarkable object 
in the heavens, by drawing a circle, and placing 
on this a mark to indicate the earth's position, 



IN THE HEAVENS. 211 

then sketch the position of the comet and the 
two courses which it may pursue. 

Referring to the preceding sketch, the comet 
vfould be said to be moving direct if its course 
were C M, because this is the way in which 
the planets move round the sun. If its course 
were C T P, it would be said to have a retro^ 
grade motion, because this is the opposite course 
to that w^hich the planets pursue. When it is 
announced, therefore, that a comet is visible in 
the heavens, and that it is moving towards the 
sun with a direct motion, a little sketch will soon 
enable us to judge whether the comet is likely 
to approach the earth, or to be visible for any 
length of time. 

We may perceive by an examination of the 
sketch that it would be quite possible for a 
comet to approach the sun, move round it, and 
travel away without being seen from the earth- 
Such a position as D, for instance, would pre- 
vent us from seeing the comet X, which might 
pass round the sun from T to 0, and thus remain 
invisible during its whole course. 



212 COMMON SIGHTS 

There are various kinds of comets, or tliey 
may visit us in diiferent stages of development ; 
for tliere are — 

Comets without a nucleus. 

Comets without a tail. 

Comets, the nucleus of which is quite trans- 
parent. 

Comets, the nucleus of which is either opaque 
or solid. 

It is believed to be an invariable rule that 
the tails of comets always point aivay from the 
sun ; so that, whichever way a comet may be 
moving, it does not draw its tail after it, but 
the tail appears driven away from the solid or 
more dense portion by the action of the sun. 
Hence " taiV is a misnomer; for a tail never 
precedes any body, but ought to follow ; whereas 
the tail of a comet retreats from the sun before 
its head, and thus imitates a courtier retreat- 
ing from the presence of majesty. 

Occasionally variations from an apparent 
rule are observable : thus, a comet which was 
seen in 1823 had two tails, one of which was as 



IN THE HEAVENS. 213 

usual turned away from the sun ; but the other, 
with a total disregard of all cometary etiquette, 
w^as turned directly towards the great luminary 
of our system. 

Many cases are recorded where a comet has 
possessed a tail divided into several distinct 
branches, some having as it were five or six 
tails. 

The size and brilliancy of the nucleus of a 
comet are no guides to the dimensions of the 
tail, some large tails being attendant upon a 
small nucleus, and vice versa. 

There are three comets in particular which be- 
long exclusively to our solar system, and which 
return at regular known intervals. These pre- 
sent peculiarities which are very interesting, and 
which have served for a fertile field of specula- 
tion. The first periodic comet, as these bodies 
are called, is named after Dr. Halley, the cele- 
brated astronomer. The other two are named 
after the tvvo astronomers who first calculated 
their orbits, viz., Encke and Biela. Encke's 
comet travels romid the sun within the orbit of 



214 COMMON SIGHTS 

Mercury on one side, and then journeys nearly 
as far as Jupiter on the other. This comet has 
revealed two very singular facts ; first, that when 
near the sun, its diameter is very much smaller 
than when at a distance : thus the sun appears 
to condense the particles of which this comet is 
composed. Secondly, the retm^n of the comet 
to a certain point does not occur uniformly, but 
there is a gradual decrease in the period. Thus, 
it might occupy 1069 days and 12 hours to 
move completely round its orbit when we ob- 
served one revolution, but merely 1069 days 
and 8 hours dming the next ; 1069 days and 4 
hours for the third, and so on with a gradually 
decreasing rate. These two facts have of course 
caused considerable speculation to be expended 
upon the results which might possibly happen 
to the various members of the system. 

We will now refer to the speculations and 
conjectures which have been offered in connec- 
tion with comets. 

Among the earlier conjectures about comets 
were those which we have already mentioned, 



IX THE HEAYENS. 215 

viz., that they come as messengers of evil, or 
were the vehicles for conveying good spirits to 
other parts of the universe. A messenger with 
a tail about thu^ty millions of miles in length 
would be rather an extravagant courier to be 
employed by the divine Architect of nature, 
whose w^orks so decidedly testify that economy 
is one principle of the universal system. 

Another supposition as to the use of comets 
was, that they revolved a few times around our 
central luminary and then dropped into him, 
and thus •' kept the kettle boihng ;" or, in other 
words, supplied the losses which, it was as- 
sumed, the sun suffered bv oivino^ out heat and 
light. In an age when a blazing &e, or some 
sort of fire, was supposed to be the only cause 
of heat, such a speculation as the above did not 
seem absurd. ISTow, however, those who reason 
amongst us would not be disposed to grant 
either that the sun is on fire, or that it requii'es 
fuel to keep it going. Such a theory also might 
explain the finale of a comet, but it would leave 
its orio'in in obscuritv. 



216 COMMON SIGHTS 

Will a comet ever run away with the earth, 
or run against it ? or will the tail of a comet 
ever surroimd the earth? are questions which 
have been gravely asked, and seriously an- 
swered. Are comets habitable ? do they pro- 
duce diseases or fogs ? and will they disturb the 
earth's motion? are considered fair subjects for 
inquiry. 

The speculations of M. Laplace upon the 
supposed effects whic^h might happen, assuming 
that a comet was solid, and that it could run 
foul of the earth, produced great consternation 
in Paris, where good situations in Paradise were 
sold to the credulous at a fah: market price, 
when a large comet became visible in the 
heavens. 

A collision is much more in character with 
the proceedings of a couple of intoxicated cab- 
men, than with those of the works of nature in 
which order, harmony, and arrangement are 
everywhere visible. 

In the year 1770 there was a comet which 
passed twice through the system of Jupiter, yet 



IN THE HEAVENS. 21 < 

it produced not the slightest effect upon the 
movements of Jupiter or his satellites. When 
a collision between a planet and a comet is 
spoken of, it is assumed that the comet is 
hurled blindly at the sun, wliilst the planet still 
rushes around its orbit, and that therefore it is 
merely a matter of luck or chance ^Yhether the 
two run foul of each other. Are we warranted 
in assuming that anything in natm-e is left to 
chance ? is it not more probable that the very 
law which brings comets towards the sun, may 
serve to keep them at such a distance from the 
planets that no disasters may happen ? A planet, 
like one pole of a magnet, may have a repelling 
as well as an attracting power ; and though at 
certain distances a comet might be attracted to 
a planet, still, if the distance decreased, this 
attraction might cease. 

It is possible, nay, almost certain, that comets 
have an use : it does not appear that they are 
required to supply the sun with fuel ; for they 
pass around him, and travel away into unknown 
regions. May they not be the agents for gather- 



218 COMMON SIGHTS 

ing up all those gases or used vapours wliieli 
may be thro\^Ti off by the sun and the various 
planets — celestial dustmen, in fact ; who come 
merely when the condition is such as to require 
them, and which are attracted by a sort of self- 
adjusting law when the system requires their 
presence ? 

From our sun they may travel to another 
luminary, and may thus serve to maintain a 
balance between various portions of the uni- 
verse ; extracting from one group that whicli 
may be dispensed with, and imparting this to 
another where it may be required. Thus when 
the comet that we have spoken of as visiting 
the Jovian system passed twice close to the 
planet Jupiter, it was probably playing the 
part of scavenger, and relieving that system of 
elements which were no longer requned. 

It is possible also that a comet, when once 
called into existence, may have a definite des- 
tination, which may depend upon the affinity of 
the particles of which it is composed towards 
various portions of the universe. For example. 



IN THE HEAVENS. 219 

a comet may perhaps move around two suns 
for a long period, until it reaches a certain 
state, when it might become merely the at- 
tendant of one of these. The comet of Encke, 
for example, belongs exclusively to our system ; 
and we see that this comet has merely a less 
dense or compact form than a planet, and a 
more elliptical orbit. This orbit is decreasing 
in ellipticity, whilst the comet is gradually as- 
suming more and more the course of a planet. 
Let these changes continue during many ages, 
and w^e shall at length have to call this comet 
a planet, as it will then diifer in no essential 
particulars from a planet with a very elliptical 
orbit. 

The fact of the comet of Encke having been 
observed to be gradually contracting its journey 
of revolution around the sun, has led to the 
conjecture that what we term space — that is, 
the intervals between the sun and the respective 
planets, &c. — is filled with some subtle fluid 
which opposes the motion of bodies, this fluid 
being termed a resisti7ig medium. Hence it has 



220 COMMON SIGHTS 

been supposed tliat, in consequence of this re- 
sisting medium, not only all the comets, but all 
the planets, will eventually tumble into the sun, 
the moons upon their primaries, and the whole 
of the bodies in the universe will be bumping 
and knockino* a2:ainst each other. 

There are one or two trifling preliminaries 
which have to be assumed before this disastrous 
state of confusion could be reached, and these 
we will briefly consider. 

The belief of the existence of a resisting 
medium arises from the following mixture of 
facts and suppositions. 

It is a law of motion that if a material 
body be given an impetus in any direction, a 
movement will take place, and continue for 
ever unless some opposition be offered. So also, 
a comet, if flung towards the sun, would continue 
to move at the same rate and time, provided 
there were no resisting medium to oppose it. 
" The comet does not move uniformly ; there- 
fore there is a resisting medium." This rea- 
soning might have passed muster in a bygone 



IN THE HEAVENS. 221 

age, when cause and effect were but little 
studied, when hypothesis rested upon theory, 
and theory upon guesses, the whole being sur- 
rounded by a maze of figui^es to protect the 
assumption from the criticism of the inquirer : 
but some further probabilities must now be 
examined before we grant any such theory as 
that all the comets and planets are going to 
tumble into the sun. 

In the first place, are we quite certain that 
comets have really been flung or launched in 
their orbits by some mechanical agency. If 
we are not certain of this, the theory of the re- 
sisting medium rests upon a guess ; whereas a 
theory ought to be based upon well-established 
facts. Again, let us grant the singular assump- 
tion that this gaseous body was launched or 
hurled towards the sun from some out-of-the- 
way locality beyond the orbit of our earth, and 
we are not driven to the necessity of granting 
that it will fall into the sun, in consequence of 
a resisting medium. AYe know that as the 
comet approaches the sun, its diameter de- 



222 COMMON SIGHTS 

creases ; are we then certain that the sun may 
not, each time the comet approaches it, cause 
the comet to become more and more solid and 
less gaseous ? In fact, to become more planetary 
and less cometary in its constitution ? Such a 
change would cause the comet to decrease its 
period of revolution, even according to the laws 
of mechanics as interpreted by us ; and the 
body, by these transmutations, might at length 
take • its place in the system, as an inter-Mer- 
curial planet, with a density even greater than 
that of Mercury, and with an orbit not less 
elliptical. 

It is always an advantage to have a choice of 
theories ; and we are impressed with the idea 
that progression in Nature's vast works is so 
much more agreeable to reflect upon than 
collision, confusion, and destruction, that we 
trust the reader will pardon the somewhat 
lengthy conjectures offered upon the probable 
use and destination of cometary bodies. 



IN THE HEAVENS. 223 



CHAPTEE XII. 

At uncertain periods and intervals there is 
visible near the northern portion of the hea- 
vens a very beautiful phenomenon, called the 
'• Aurora Borealis." The aurora presents during 
a very short time various changes, which, for 
the sake of distinction, have been designated 
by different names. 

The first indication of the advent of an aurora 
is a light appearance in the northern sky, 
somewhat similar to the dawn of day. This 
light is usually seen about one or two hours 
after^ sunset, and has been called the aurora 
twilight. This "twilight" varies in intensity, 
and serves as an indication of the coming 
aurora, which should be looked for during the 
evening. 

As the evening advances arches of light, in 



224 COMMON SIGHTS 

form somewhat like a rainbow, may be seen to 
stretch from the north-east round to the north- 
west ; these arches are usually pale yellow or 
whitish. 

From these arches, or from some dark smoky- 
looking clouds which usually rest near the 
northern horizon, several streamers will be seen 
to shoot up from the north towards the heavens 
above us. These streamers are bright, and 
conamonly pale blue or pink, and they flash 
and rush upwards with great rapidity. 

A circle of either pure white or of various 
brilliant colom^s, with streamers shooting out 
from it, is frequently observed during the 
aurora. This circle is usually around the point 
in the heavens towards which the pole of a 
balanced magnetic needle would point, and it 
is called the corona. 

In addition to the streamers there are some- 
times undulations or waves of light, which flow 
upv/ard towards the corona or along the line of 
an arch. 

In addition to the above there are milky sort 



IN THE HEATEXS. 225 

of clouds, which have a self-luminous appear- 
ance, and which prognosticate the intensity of 
the aui^ora. 

In England the aurora is not a very common 
phenomenon ; but in North America and in 
northern regions it is frequently visible. Still, 
if an individual is acquainted with the pre- 
liminary indications of the coming aurora, he 
may frequently observe this beautiful and 
mystical effect. 

A very beautiful aurora was visible on the 
evening of the 9th March, 1861 : a description 
of this may serve to explain the general appear- 
ances of the phenomenon. 

At a very short distance above the northern 
horizon, and at about half-past 8 p.m., there 
gradually appeared a sort of green-tinted twi- 
light, as though the sun were going to rise. A 
few dark clouds then gathered in the centre of 
this light, which soon varied in intensity, some 
faint pale-bluish streamers then shot upwards 
from the N.jST.E. and from the N.X.^Y. points of 
the horizon. These streamers reached nearly 

Q 



226 COMMON SIGHTS 

overhead, but as tliey ascended tliey changed 
their hue, and became of a warm rosy colour. 
They extended east and west, lost the streamer 
form, and illuminated the heavens just as though 
some large fire were ^casting reflected light into 
the sky. These ajDpearances came in flashes, 
and there were intervals of several minutes 
when no streamers were visible. The aurora 
continued during nearly two hom^s. 

From observations which have been carried 
on during upwards of a centm^y, it is found that 
the greatest number of aurorse occur in the 
month of October, and the fewest in June. The 
ratio being as follows : — October, March, No- 
vember, September, December, February, April, 
Januar)^, August, May, July, June. This ratio 
it is believed is liable to variation, which some 
inquirers suppose to be periodical. 

It has been found that at certain periods, 
both during the day and night, there are cur- 
rents of a subtle element rushing over the 
earth's surface. These are usually called mag- 
netic or electrical currents, because they cause 



IN' THE HEAYEXS. 227 

a magnetic needle to slightly vary, and also 
produce singailar effects upon the needles of 
the common telegraph. AYhen an am'ora oe- 
cm^s these disturbances are considerably in- 
creased, and it is sometimes almost impossible 
to send a telegraphic message when an aurora 
is in force. The aurora is seen best in the 
higher regions of the earth, and better in the 
western continent than in the eastern. From 
these facts we are at once led to conclude that 
the aurora is probably a magnetic phenomenon. 
We are not yet aware how the proper balance of 
electricity or magnetism is maintained upon 
and in our earth, nor are we yet made acquainted 
Avith the exact relation which exists between 
these two forces. We know that electrical 
storms occur at certain interrals, but we are 
not fully aware of the cause of these, which 
after all must be merely the effects of other 
effects. It may be then that, when there is a 
superabundance of magnetism in the earth, this 
surplus is discharged from both magnetic poles : 
the rapid passage of the magnetic element 



228 C03IM0N SIGHTS 

through the atmosphere producing light. Hence 
it is probable, should this supposition be true, 
that at the same time an aurora would be 
visible both in the northern and southern re- 
gions. It is possible that this may be the case 
for many other reasons, which would, however, 
be beyond the course of this little work to 
adduce. 

A very little observation directed towards 
the • northern horizon soon after sunset, es- 
pecially in February, March, September, and 
October, will be rewarded by a ^^ew of the bril- 
liant phenomenon called the Aurora Borealis, 

METEOES AXD AEEOLITES. 

At various times of the year, but particularly in 
the month of August, a brilliant star-like object 
may be seen, which shoots along the sky for a 
short distance, and either disappears as though it 
** went out," or bursts with a loud report. These 
objects are commonly called meteoes, aeeo- 
LiTES, or SHOOTIXG STAES. The fall of these sin- 
gular bodies afforded one of the many examples 



IX THE HEAVEXS. 229 

of the danger that surrounds those men of 
science who believe that they have solved all 
the laws of nature. '' The Academy of Sciences," 
says 31. Arago, " declared in 17(19 that the stone 
picked up at the instant of its fall at Luce, by 
several persons who continued to perceive it 
until it reached the earth's surface, had not 
fallen from the heavens," and the savants of 
Europe affirmed '' that the fall of stones from 
the atmosphere was impossible/' As M. Arago 
justly remarks, " It is certain that physicists 
who refuse to admit any facts except those 
which they perceive to admit of explanation, do 
more injury to the progTcss of science than men 
who are liable to the reproach of being too 
credulous." 

It has been found that in nearly all the 
masses which have been ascertained to have 
fallen from the atmosphere, there is a prepon- 
derance of nickel. Some of these masses are 
hard, whilst otliers are spongy. 

We have the record of several accidents 
which have been caused by aerolites : and when 



230 COMMON SIGHTS 

we consider the weight of some of these bodies, 
it is not remarkable that accidents should occur. 
In 1674, a ball weighing nine pounds killed 
two men on board a Dutch East Indian vessel. 
An aerolite fell in New Granada in 1810, and 
weighed upwards of sixteen hundred pounds. 

Globes of fire which suddenly appear and 
then vanish are usually termed bolides. 
Sometimes bolides give out a very bright light, 
or leave behind them a train of fire ; occa- 
sionally they burst into several pieces, which 
form those falling bodies of which we have 
spoken. 

Aerolites have afforded a fine field for con- 
jecture, since men of science admitted that they 
were possible. It has been supposed that a ring 
of these bodies revolves about and surroimds the 
sun, and that the earth passes through this ring in 
August, when, consequently, the greatest num- 
ber become visible. Other speculators imagine 
that they are fired out of the volcanoes in the 
moon. But, as we do not yet know that the 
lunar volcanoes are active, and we have to 



IN THE HEAVENS. 231 

assume a Yelocity of projection of upwards of 
eight thousand feet per second, this conjecture 
is rather baseless. It may be possible that the 
elements of which asteroids are formed exists 
in space, and that these become soUdified by 
agencies occasionally at work, and which may 
be induced by the earth's electrical or magnetic 
state, just as water may be formed from its 
elements by the electric spark. 



THE END. 



LONDON : PRINTED 3T WILUAil CLO"^ES AND SONS, STAMFORD STREET. 



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